Here's my guess. It's a guess so take what it's worth and get yourself a cup of coffee.... QT not Starbucks.
Our coaching staff knows good and well that OL is our #1 need. Sark said as much. Last year I think they failed to recognize the need... this year they know it. Therefore, they had every intention of signing two or three top-notch, plug and play OL and a few younger OL to develop. The problem isn't that they're prioritizing backup QB or that they don't know. If there is a problem, or blame to go around.... it's that they failed to win the recruiting battles for the top notch players they wanted. I think they went all in for the Guard and Tackle from MeChicken... and fully expected to get both. Both went back to Michigan for less money than Texas offered. I think this took them by surprise.
I don't know what else has happened.... but I imagine it has been similar to what happened with the Michigan OL-men. Sark said OL was a priority... so I assume they tried. I don't think he forgot and I don't think he decided not to pursue OL in the portal because he is satisfied with what's on campus.
I hope there is still a player out there, with starting potential, that Texas can go after.... if not I expect the starting lineup to be: Goosby, Baker, Robertson, Cujoe and Siani.