That may explain your rose-colored adoration of Book. If not, you may want to remove your mouth from Ian's organ and see what his career amounts to before you compare him to two all time ND greats.
Theismann? Are you crapping me? The comparison to Clements is probably more apt (if incredibly shallow) than any wet dream of your comparing him to Theismann. And I have seen Clements play in person as well as during three years of practice. The funniest thing is in your comparison is that Book is not a good downfield passer at all so saying the Clements wasn't in comparison is really goofy. How you could conclude anything re: their respective arm strengths when you never saw Clements play in person is nothing short of idiocy.
Noting that Clements didn't play in the NFL as evidence of anything is equally as goofy since Book will never even see an NFL practice squad much less play in the CFL where Clements happens to be a CFL Most Outstanding Player, led that league in passing once, won two Grey Cups and was a 7 time all star. His career completion rate in the CFL is 60% so saying he wasn't an accurate passer may be one the dumbest things you've posted. I wouldn't even start comparing him to Theismann.
All in all, trying to compare across generations of football is really fucking stupid. You don't know how Clements would function is this era of pass happy offenses any more than you know how Book would function in Clement's era.