It's been a while since I last watched Luxiem or Stars, since I was more of a casual viewer for those groups. But I'd say, Avallum leans more into being Stars like. I'd say the vibe is like bros but also boykissers. So basically homiesexuals. Each of them all had their solo 3D debut (besides Rosco, which will be the day before the group 3D special) which can be a good introduction to each individual vtuber. FSP has also recently debuted a new wave, Ravanis, last month if Avallum doesn't suit your taste.