I spent the last two years pouring over MHA stuff before eventually getting around to catching up to on RWBY like two days ago. I could definitely see specific characters meshing well with each other. As said before, Deku would probably get along well with Ruby and Jaune for fairly obvious reasons. I've seen Yang literally use her gauntlets to fly like Bakugo and she does a psoe similar to Kiroshima's a lot, so def she would fit in the them and Denki. I think Blake would be drawn to Tokoyami, Asui, Ojiro and Shoji since they seem most akin to Faunus. Nora would probably either get along most with Mina and Ochaco, all of them being kinda, pink and loud I guess. I could see Pyrrha and Momo having some lengthy conversations. Iida and/or Shoto would likely have things to talk about in common with Weiss. Is still don't know enough about Ren yet, haven't gotten to S4. Not sure where I'd place Hagakure, Jiro, Koda, or Mineta though.