How you think that Hatton is a smarter fighter? Have you seen Cotto fight?
Heres what both guys do better than the other
Cotto is much more accurate, he has better speed, and hits harder. To go along with this he also has better boxing skills.

Hatton has better footwork, and he is a better inside fighter... he will be on your ass from start to finish which is something Cotto will not do. While Cotto does put pressure its more calculated, and delibrate. I say Hatton makes it a hard fight for Cotto because of his ability to fight on the inside... however I can't see him winning this fight... He can't take body punches all that well, and I think Cotto will bust his face up with that jab, then he will bust Hatton's body up with that left hook... from hell.