Tony Pollard is the same thing the Cowboys did with Marion Barber. That is they made the complimentary RB in a duo the lead RB when he's best suited for the complimentary role. As a result, he's a disappointment in the lead role because he's all about efficiency, not volume.
In other words, he misses Zeke. They don't have a RB that can pound it between the tackles on a regular basis. I don't expect Pollard to suddenly improve. I do expect him to gradually wear down as the season goes on. He'll be and RB2 at best.
Taylor I think is the much better prospect for a break out. You have to figure that the Colts didn't just give him a contract extension after a hold out to play 2nd fiddle. The main concern is that Moss seems to be the guy who is gonna get it at the goal line.