fighters are matched by weight and not by the toughness of the chin. weight is not even a good gauge for even playing field as there are situations when opponents have the same weight but one is bigger in size than the other and some big dudes still are very capable in cutting much weight.
Canelo been cutting hard, early. Had to match GGG's 30 day weight, for reasons of public perception :deal
I saw a comment by fighthype.com's youtube channel that said after visiting both camps he considered Canelo to be the bigger fighter. I have to say that from pictures and videos it does look Khan is the same, or even on the edge of larger. But the OP picture is a bit dated when Khan had neen bulking and probably at his largest with fat gains showing.
Khan could be taller and have longer reach than Canelo. But Canelo has more body mass and muscle. I don't like the way Khan looks at 147. He's much slower footed than he was at 140. He was getting tagged by Algheri and Diaz. Not sure what weight he plans on coming in but this could end in tragedy.