Saying that he can c/r 77-TT for value on the turn implies that we're calling with any Ace high. Realistically he's never going to be ahead when called, so he can't bet those for value. It's true that some guys will do that but they probably don't know why they're doing it and we can't expect them to do that all the time with all of their range. You can say: ok, I've seen this a lot, so I will add 77-88 to his range. That's good if that's your observation. But just because there's a chance that he might sometimes do that with those hands doesn't mean we can put all of those hands in his range.