I know the Zeke contract is making us all very hesitant to spend money on an RB, but I say extend him, if they plan on using him the right way, as a weapon, and not strictly as an RB, that catches the ball once or twice a game on simple flares. He should only get about ten conventional runs per game, let a rookie get the other ones. Instead, he should be used all over the field.
A couple of things to keep in mind:
One, by the end of his fourth year, he had way fewer touches than Zeke at the same point of his career. I think he has three more good years.
Second, his running style is very different than Zeke. Zeke liked to take on guys to end plays, and it cost him. He ran much more like MBIII. Pollard likes to avoid contact and will often run out of bounds to end a play. His running style is much more like Emmitt's.