I think you may be underesimating how much of a difference it makes in Texas football to have some talent around you. I've heard that Witt plays in arguably the toughest district in Texas, that means there are some REALLY good teams he going against. Witt's teams just moved up to this level this year.
Look at it this way (not a great analagy, but kinda close) Pretty much everyone would agree that Peyton Manning is the best QB in the NFL. He played on a pretty good team and has quite a bit of talent around him. Now, put Peyton on the Raiders, do you really think he would have as good a year as he does with the Colts? I don't think so. The Raiders have no o-line and other than Randy Moss (and maybe LaMont Jordan) not a whole lot of talent.
My guess (again, I haven't seen any of Witt's games) is that his o-line does get pretty much dominated when they go against some of the better teams in the state. If you are under constant pressure and don't have playmakers on your team in the first place, it's going to be hard to win games, let alone put up big stats.
I trust that our coaches know what to look for in a QB, he was also recruited by some other coaches that know QB's (Leach, Spurier, etc) And the best part is he will be here in January and won't even have to compete for the starting job until he has a year and a half of learning the system under his belt.
JMO
Go Big Red!