Last year's O was dynamic because of the pace and precision of the short and intermediate passing game, combined with Nassib's ability to read coverages, make quick decisions, and get the ball where it needed to be. The O line did their part in pass protection (this was also huge), which forced teams to play honest in the box and/or walk LBs off to take away slants. That is what opened up the run game. From there, I am sure the goal was to use play action to open up the deep passing game - this was not Nassib's strength and, ultimately, it was not a huge factor.
The point I'm trying to make is, the running game, despite the depth and talent at RB, will NOT be dynamic this year without at least the threat of the short and intermediate passing, IMO.