I think Boyle was given a lot of opportunity maybe too soon for him. The drop off from Shireffs to Boyle was huge. Lagow was overlooked.
I went to the open practice in 2013 and I remember Boyle throwing the ball so fast that I actually heard it hissing from the sideline where I was standing.
but you are correct, Shirreffs was the better college QB. It happens quite often. Boyle is also having a better pro career than Heisman winner Johnny Manziel and many other high profile college QB's.
This is also why we can't completely write off a QB like Millen, he might suddenly blossom into a solid starter under someone like Charlton. The physical skills are there.