I read once that on Steven Universe, they didn't have specific heights in mind for the characters, and allowed things to be more elastic. The important thing was "character A appears bigger than character B", etc. I like that philosophy and think it's probably useful for a comic like this, where there are a lot of height differences that I don't really want to be too ultra-specific about...

Anyway, please chalk up any mistakes in that regard to "artistic license", haha.