Shawn Marion, fiercely proud and a little defensive, was fond of telling reporters during the height of the Seven Seconds or Less Era in Phoenix that players made “genius” coaches like Mike D’Antoni look good.

Marion is obviously oversimplifying. Head coaches are hugely important, maybe third on the importance hierarchy in any franchise, behind only the owner and the franchise superstar (if one is present). There are a few reasons why Chicago will rank among the three or five best defensive teams this season and going forward, but Tom Thibodeau’s presence is probably the biggest factor.

But a coach can only work with the players on hand, and the Lakers’ roster brings some structural issues — largely outlined here — that were going to challenge whomever the team named as Mike Brown’s in-season replacement. In a shocking reversal, they’ve chosen D’Antoni’s spread pick-and-roll system over the triangle and Phil Jackson, whose salary demands and requests for broader organization control were apparently too much for the Buss family, per the Los Angeles Times and others. Inking D’Antoni to a three-year deal, with an option for a fourth season, may also be a signal that the Lakers believe his style is a better fit for the only pieces — Steve Nash and Dwight Howard — on the books beyond 2013-14, assuming the Lakers convince Howard to re-sign this summer on a max deal.

The other stars, Kobe Bryant and Pau Gasol, are Jackson acolytes and Triangle wizards, and Jackson’s 11 rings stand as evidence he may have been the very best choice for the 2011-12 Lakers. If D’Antoni was a second choice, he stands as a very fine one. You know his history with Nash. Those Phoenix teams were not just great offensive squads; they were some of the very best in basketball history. D’Antoni and Kobe Bryant are tight dating to Bryant’s childhood years in Italy, where D’Antoni was an elite player, and now to D’Antoni’s work as a longtime Team USA assistant. Howard may be the most efficient pick-and-roll big man in the world, and the Lakers will now build their offense around Howard and perhaps the greatest pick-and-roll point guard in NBA history. That will drive Bryant into a secondary role, but he has already shown that he can thrive finding easier buckets as an off-ball cutter and post-up beast against weaker defenders. Pau Gasol will find his spots, because he’s Pau Gasol and that’s what he does — all while making everyone else around him better with his next-level passing.

D’Antoni is a very smart guy. He will adapt his offense to fit the personnel here; Phoenix remained an elite offensive team despite some pretty major roster shakeups, including the loss of Joe Johnson to free agency; the absence of Amar’e Stoudemire for essentially the entire 2005-06 season; and the presence of a paint-clogging Shaquille O’Neal in the last part of the 2007-08 season, when the Suns ranked no. 2 overall in points per possession and scored just as efficiently with O’Neal on the court as off.

There are challenges, obviously:

• Nash turns 39 in February and has a small fracture in the fibula of his left leg. D’Antoni’s entire offense is based around Nash’s combination of historically great shooting and play-making, and if Nash can’t be 90 percent of himself when the games really matter, D’Antoni will have to adjust accordingly. Bryant is a solid pick-and-roll ball handler who has long worked as the team’s best off-the-dribble creator, but he can’t replicate what Nash does. Steve Blake gets into the paint off the bounce once or twice a week. Chris Duhon could barely cross half court last year without throwing the ball to the other team, though he played well under D’Antoni in New York. Darius Morris is an almost total NBA unknown.

Again: D’Antoni is smart enough to adjust for any long-term Nash limitations, and any team with Gasol and Howard could build an effective inside-out offense in a pinch. But Nash’s health is paramount if the Lakers want a realistic shot at getting through at least three very tough playoff series — and perhaps four, depending on their seeding.

• The same spacing issues are still here. Bryant is an average 3-point shooter. Nobody pays any attention to Metta World Peace on the perimeter, even as Peace has built himself into a league-average 3-point shooter, especially from the corners. He’s too slow now to replicate the Marion role as a weak-side kickout option capable of catching a skip pass as the defense wanders from him, and then driving hard into the lane for a layup or floater. Gasol’s range extends nicely to 20 feet, but he needs time to set his feet from there, and he won’t do much for you standing behind the 3-point arc.

As I wrote Friday, Gasol is a center who for the last two years has been forced into a square-peg-round-hole fit alongside another low-post center. Lamar Odom is no longer around to space the floor and break up the two-center effect. It was never ideal that three of the team’s four best players rarely played together as result of the spacing issues Odom presented as a small forward, but his versatility allowed the Lakers to maximize what they had.

You can pack the paint on these Lakers. Nash is by far the best shooter on the team, and one reason the Princeton offense made some sense was the idea that the Lakers could benefit by using Nash away from the ball as a spot-up threat to whom defenders could not yield even a sliver of space. Nash will be on the ball all the time now, meaning the four defenders away from it won’t have to worry about a single elite long-distance shooter.

There are remedies. Bryant has long been one of the best cutters in the league, a fact that made his determination to ball-hog all the more irritating. Antawn Jamison, one of the only useful players on a thin bench, might work as a capable long-range shooting power forward alongside Howard, instead of in the weird small forward role in which Brown used him. World Peace is in great shape, cuts well, and, like Kobe, can do damage in the post against the right defenders. Gasol’s passing makes a cramped floor feel less cramped.

Jodie Meeks is also here, though Brown sort of forgot about him. Bryant has often slid to small forward, especially when both Jordan Farmar and Shannon Brown were around and moderately productive; it would not be a surprise if D’Antoni took an extended look at a Nash/Meeks/Bryant/Gasol/Howard lineup.

But the roster is never going to be ideal, which is why Gasol trade rumors will never stop. D’Antoni’s system worked with everyone in Phoenix, but it worked best with Stoudemire as the lone inside force, diving to the rim in beautiful concert with Nash as shooters dotted the perimeter around them. D’Antoni has two inside-first bigs now and so-so outside shooting among his starters. This will be a challenge, but the Lakers should rank among the league’s 10 best offenses — as they do now — regardless of system. The talent is that good, and talent figures things out. But champions usually rank better than that, and they’ll need to find a top-five level of play on at least one side of the ball. Which brings us to:

• Defense. Spare me the nonsense that D’Antoni doesn’t coach defense, or that his Phoenix teams were terrible defensively. They ranked right around the league average in points allowed per possession during most of his tenure there. Our collective addiction to points per game and (declining) ignorance about pace made it appear the Suns were hemorrhaging points like the Warriors. They weren’t.

Nor were D’Antoni’s Knicks, at least the version that was actually trying to win games instead of engaging in a prolonged LeBron James roster tear-down. The Knicks ranked around ninth or 10th in points allowed per possession when D’Antoni resigned, and though they improved under the defense-first Mike Woodson, the absence of Stoudemire, and Carmelo Anthony’s sudden decision that earning $20 million meant he should actually try hard, had something to do with that improvement.

Please also spare me the dreck about how D’Antoni’s system “failed” in the playoffs or “can’t win” titles. Two conference finals berths in an ultracompetitive West is not a failure. The Suns suffered a disproportionate amount of bad luck in the postseason. Joe Johnson’s orbital fracture cost him the first two games of the 2005 conference finals. Stoudemire was out for the entirety of the 2006 postseason, and several other key guys, including Raja Bell and Kurt Thomas, were in street clothes for part of that run. The suspensions of Boris Diaw and Stoudemire for Game 5 of the conference semifinals against San Antonio in 2007 shifted the entire series.

Luck is a factor in every playoff run. So are injuries. You don’t have to go back even one year to realize that. You could also ask Jerry West about luck, health, and the difficulty of winning even one title despite a “clutch” reputation. The people who ignore luck, injuries, matchups, and a dozen other variables that help determine the league championship every season are the same people who said LeBron would never win one because of some internal weakness.

There are examples, too, of teams that won titles or nearly won them using the Phoenix model of fantastic offense and average defense. The 2010-11 Mavs blew the doors off everyone in the playoffs while allowing points at a league-average rate during their postseason run. That understates how good the Mavs were defensively, since they were top-10 in the regular season and faced some of the best scoring teams in the league during the small playoff sample size. The 1994-95 Rockets had a similar offense-first run, playing just good enough defense against four scoring machines.

But such runs are the exception. A top-10 defense is a borderline must-have for any team that wants the title. Even some of the very “worst” defensive teams to seriously contend for a ring or even win one — the 2001 Lakers, 1998 Jazz, and 1994 Rockets, for instance — turned mediocre regular-season defenses into stingy playoff juggernauts. Neil Paine’s essential research at Basketball-Reference has shown that an elite defense is slightly more important in winning a title than an elite offense, though both are crucial.

D’Antoni’s Phoenix way can work, but it is not ideal. The Heat were able to weather their own bad injury luck in part because, even without Chris Bosh, they could lean upon a very strong defense.

The idea that D’Antoni doesn’t coach defense is ridiculous. It’s all over Seven Seconds or Less, Jack McCallum’s must-read book about the 2005-06 Suns, and one conversation with the guy or a coach who has worked with him will reveal that D’Antoni talks a ton about defensive Xs and Os. He has a lot of ideas to guard Star Wing X, and he knows very well that Big Guy Y likes to spin baseline on post-ups.

But it isn’t his specialty, and he has never had a rock-solid system on which to fall back. He’s had a few assistants that specialized on that end; Marc Iavaroni helped in Phoenix, and Alvin Gentry brought some old-school “knock him on his ass” toughness. But neither brought anything close to Thibodeau-level tactical brilliance and fundamental soundness. It’s hard to imagine a coach from any really good defensive team saying what Gentry said before a 2006 conference finals game against Dallas (via McCallum’s book):

“I’ll be honest with you guys. If you asked me right now what we’re supposed to do if Jason Terry and somebody screen-and-roll, I wouldn’t know if we’re doubling, trapping, or doing nothing. I just think we’re getting too many things going on.”

D’Antoni is a tinkerer, but he’s not a defense-first guy, and he has lacked a systematic approach. He famously turned down a chance to hire Thibodeau in Phoenix as a defensive specialist.

Of course, he’ll now have Howard, the very best defensive player in the league when healthy. That may be all it takes; how good might Phoenix’s average defensive teams have been with Howard in Stoudemire’s place?

We’re going to find out as the latest Lakers’ mini-season — D’Antoni without Nash — begins shortly. Nash’s return will mark the start of another season in what promises to be a drama-filled campaign. D’Antoni, at least, is used to drama.