Is this as simple as Buddy outboxing Tito for a while until Trinidad catches up and knocks him out? Or is there more to this matchup?
Well, you asked for the best available McGirt, but that version was 140. With the exception of the Simon Brown fight, I thought his welterweight run ranged from mediocre to ordinary, and that he looked much better at junior welterweight. Ah fuck it, it really doesn't matter. P4P or even straight up at 147, If Trinidad doesn't eventually knock him out, he rides a strong 2nd half en route to a wide points win. At 140, it'd be different, McGirt was at his best while Tito was just a pup. So, Tito KO2 at 140.
Tito stops any version of McGirt, even the one who outboxed Brown. Tito was alot quicker, and rangier than Brown, with more power. McGirt's skill would give Tito trouble early but overall, Buddy just doesnt have the size, quickness and overall ability to pull off what DLH did against Tito at 147. Tito by late KO.
Trinidad either stops Buddy late in the fight or floors him a few times to take a clear-cut decision. He'd be befuddled early and would take some time to start landing with consistency, but I think you need more than what McGirt could bring to the table to beat Trinidad, even as overrated as he was. (he has since become somewhat underrated, to the point where basically anyone with boxing ability is picked to flog him, which is pretty ridiculous)
Trinidad via late stoppage. McGirt would trouble him early but Tito would find the range and break him down.