The only down side is that Gore hasn't missed a game due to injury in years
(good for him!) so the chances of Mack winning the starting role is likely to be gradual and not overnight. I also think the Colts are probably hesitant to straight up bench a solid veteran. However, I do see a lot of upside in your pickup since Mack is the more explosive RB in Indy and I agree he'll be winning the job, or at least a larger share of the touches, toward the last half of the season. Who knows!
I picked up Elijah McGuire for my dynasty league two weeks ago...hopefully he'll pay off.
Best of luck!
RE: My big waver wire addition came through for me