Barber is in a rotation backfield in Dallas. Felix Jones AND Tashard Choice have been getting touches, and they are up against an improving D in SD. Combined with the fact that Dallas is pass-heavy recently, and I'd not touch this with a 10-foot poll.
Ganther, while a total risk play in that he's unknown, has a very soft matchup, and the Redskins have traditionally been a run-first team. Their offense has improved a great deal since they hired their new play caller. Zorn must have seen something he liked to give Ganther the start over a career backup in Cartright. In your situation, I'd start Ganther.
I have a similar question on my own squad! Help with mine?viewtopic.php?t=464194viewtopic.php?t=464192