That's why I paid so much attention to their clothes (damn
Alice: Madness Returns game, why I played it?
). If EQG's bodies look almost the same, nice detailed outfits can be used to give them some individuality. Unlike ponies, those girl's garments are important parts of them. Of course, some outfits look weird and bimbo-like, but many characters have really nice suits, especially after 2017 redraw.
And their haircut already gives them different shape (remember the «Good Vibes» title card?).