Exactly, even haye accepted he had a vulnerable chin when he stepped up to heavies and like it or not adapted his game accordingly.
both haye and khan dont have as bad chin as is made out. differance is haye knows he's not the best at taking a shot and tries to avoid it or stack exchanges in his favour by only engaging against slower smaller guys - credit he even stood up from a monster right hand from wlad. khan on the other hand thinks he's prime lamotta and engages in exchanges at any opportunity.