Perhaps one way will be to use Gurley on 1st downs, and any 2nd down where the distance is 4 yards or less, and 3rd downs where the distance is more than 4 yards. Then Use CJ on 2nd downs where distance is 5+ yards, and 3rd downs when distance is 4 yards or less. The logic here is that Gurley is far more potent as a receiver (vs CJ)....so let him do his damage on 1st down....or 2nd downs were the distance is short (great passing down). In 3rd and long....where they need better receiving, Gurley plays. CJ can play on 2nd and long because he can carry the ball twice to get a first down (he's almost a certain 4 or 5 yards per carry). Also, on 3rd and short....let CJ get the pounding.
The problem is the McVay doesn't like to change personnel if he wants the upbeat tempo. So changing them out based on down and distance is sort of counter to how McVay operates. So maybe, he just lets Gurley go a series.....then CJ, then alternate.
You also have to consider how many "touches" each player needs. Gurley seems to have been the type of player that needs touches to get going. Yet CJ seems to be fine getting the ball whenever you can get it to him.
I think it goes without saying that if the Rams are up....and the point differential (vs the time) necessitates switching to ground-n-pound to eat clock (Playoff football). Then go all CJ with the 12 personnel. Just wear 'em down and rest Gurley for the next week.
