No, he's not.
He ran a 4.72 and a 4.73 at The Combine and until yesterday, he's looked far slower than that on the field.
He looked more comfortable with his assignments against the Browns but he is not the type of running back that can take nothing and turn it into something. His scouting report matches up perfectly with what he's shown the past 2 seasons:
Strengths
Built like a bruiser and runs with good physicality
Sturdy base absorbs hits and maintains balance
Doesn't get cute
Makes decisions early and lives with them
Keeps pads square to line of scrimmage and slides from gap to gap without losing momentum when searching for the best running lane
Has good lateral jump cut to elude initial tackle attempts at the line of scrimmage
Runs under his pads with good forward lean near the goal line
Has size to be utilized as a short yardage option
Very comfortable handling swing passes and check downs and showed an ability to extend drives out of the backfield
Highly respected teammate and named a team MVP this season.
Weaknesses:
Doesn't feel running lanes developing, needs to see it
Burst through line of scrimmage is below average
Doesn't have the feet and instincts to sting moves together
Doesn't search for late cuts and may not be able to make them anyway
Doesn't generate as many yards after contacts as teams might like
Won't get many unexpected yards
Slow to gather and cut downhill when asked to run an outside track
Needs downhill play calls
Top heavy running style limits ability to make sharp backside cuts
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His weaknesses are why he went undrafted.
https://chiefswire.usatoday.com/2018...rrel-williams/
https://www.theadvocate.com/baton_ro...113a66b23.html