Good question. Not a lot really! One time someone said Jon looks like Ginko from Mushishi and I don’t mind because Ginko is great.

A few times I’ve heard that Elias is like Hughes from FMA but it’s actually a pet peeve because both wear glasses + uniform and that’s where the similarities end also that is the worst ahoge I’ve seen

Advice though: if you ever think an artist’s work resembles another artist’s work, DON’T tell them (unless it’s literally ripped off and needs that criticism). You may think it’s a compliment but most artists don’t appreciate it. They want to be viewed as their own person, not a knock-off of someone else.