Funnily enough, I'd look upon a fanfic that casts Enjolras as Jason in the same manner as I would the one who casts Ramin. At that point, you're writing thinly-veiled RPF. It's why I can't stand fanart that depicts Enjolras as an actor as well. It's not Enjolras, it's just that guy portraying him. And each actor has their own interpretation. So when a person uses that, I assume they're illiterate, half-baked idiots. Severe, sure, but I have no patience to spare.

It's why I don't read anyone's fanfic, really, save for the ones posted here.