The player that I remember gave McCoy a hard time was Darnell Jackson. Jackson basically over powered McCoy more than once in the FSU game.
Some players are just better suited for OT rather than OG Jalen Rivers was a disappointing OG, and a really good OT. But most people doubted that would be a good OT because of his struggles at OG. But each postion requires different skills and the opposition is different. Rivers was over powered by DT’s, but not by DE’s. The hope is that McCoy has a transition similar to Jalen Rivers.