Oh man please don't deify models, I bet not even they like it... well maybe Coco and the rest of narcissist ones, but the down to Earth ones say in their interviews they like to be treated like regular people... I know that's your personal opinion, but saying Simon doesn't have physical flaws is just as false as saying he's not pretty. Now, of course people who doesn't care much about fashion and are used to think that Hollywood stars and football players are the definition of hot, would say Simon or Sean are more attractive than Clement... and the explanation for this relies in the simple fact that Simon's and Sean's beauty is more common than Clement's... or maybe the right word is more obvious; they both have some facial features that give them the modelesque look, but their faces are what the mundane brain is used to relate with the concept of male beauty: the action heroe from a blockbuster, the stereotypical Disney Prince... classic face, big muscles, lips and hair... it's easy to read beauty in them.
Now Clement's beauty is not obvious at all for the regular eye, starting because most of it belongs to the renaissance aesthetics, even though it does have this modern twist... that's why it wants be classic but at the same time has this quirkiness that makes him so interesting (not that classic beauties can not be interesting, they're just easier to define). His facial proportions are perfect and unperfect at the same time, and his lean body is muscularly defined to the perfect balance where he can fit like a glove the different aesthetics of houses like Prada and Gucci the same season. Mix all that with an adorable smile and a cool personality and there you have another definition of sexiness, that of course, if it's true, not every one has to love it... it's also a fact... not everyone is able to see it.