Betting lines are obviously an attempt to pull reasonably equal money to both sides, in general. A close line can mean they skill levels of the two teams are well known and fairly equal. It can also mean there's huge uncertainty for one or both teams and the betting public thinks they've got an inside idea.
Right now, I believe that there's a reason wealthy donors spent 8 figures to dismiss the previous staff. I believe that Flood and Sark learned that they could insist on the offense they want, or win games with the offense they have. They've chosen to optimize the latter. I believe that the Texas defense is understanding how their positions work. They also have to stop three legit drives before the opponent is in desperation mode to keep up with the scoring.
However...
Two games isn't proof, especially considering the teams in question. TCU is a huge bugaboo. Saturday is another opportunity to exorcise a demon from the Longhorn temple, but until proven otherwise, they're still a roadblock.