I think overall it's just VERY hard to find quality OTs coming out of high school. After Alabama, Georgia, Ohio State, Notre Dame, Michigan, USC, LSU, etc. get their pick there aren't a lot to go around. Sean Callahan has noted several times over the last few months that even some the best Pipeline tackles from the 90s played guard in the NFL. So until we start competing on the national level - or have a really good in somewhere - we're probably looking to mostly get some "project" guys and hope to build them up from there.
Farniok was barely a four-star but even when he was in high school there were rumblings that he'd end up at guard. Jaimes was a higher three-star but not that close to a four-star. Brokop was about the same but flamed out. Gates was barely a four-star and was pretty decent but is a guard if he makes it in the NFL. Paul Thurston was a mid-four-star but didn't pan out. Tyler Moore was the last solid four-star OT we got but ran into personality issues. Even in the supposed Callahan recruiting boom we got basically nothing for highly-rated OT recruits.
Just a very hard position to recruit.