I am all for playing the better player, but the smart move here strategy-wise is TVD.
If you start Garcia and he struggles, which is entirely possible for a QB in his first meaningful action (IDC how bad UNC's D is), you have a real problem on your hands. Do you then bench Garcia and bench your 2nd QB this season only to revert to TVD (whom you've already benched in favor of Jake)? Now you have real confidence problems with both QBs.
Conversely, start TVD. If he plays well, you can rationalize MTSU as merely a bad game. If he plays poorly, then you've given him every opportunity to prove it and Garcia is the only option at that point.
In other words, ride TVD until the point he becomes unplayable. Otherwise, you risk jumping the gun too soon on a QB that may not be ready and face questions/lingering doubts whether he should have stayed with TVD.
(I can't believe we're having this discussion.)