Can't wait for RWBY: Grimm Campaign. Sounds like it'll be great, and I hope they eventually will publish their home-brew rules for others to try out.
BTW, I've actually gone through the process of making D&D versions of RWBY characters (not using home-brew stuff, but using spells and other features to mimic their abilities and gear). Not going to get into the specifics, but when it comes to skill proficiencies offered by backgrounds, I do engage in a bit of tweaking by swapping one skill given with a more appropriate one. Then again, the Player's Handbook does allow for custom backgrounds where you can mix and match, so it works. Some Unearthed Arcana is involved as well, but nothing that would be considered too much to ask a DM for approval.
- Ruby: Variant Human (or Scourge Aasimar) Folk Hero; Battle Master Fighter 6/Celestial Warlock 3/Divine Soul Sorcerer 11
- Weiss: High Elf Noble; Battle Master 7/Bladesinger Wizard 13 (yes, I know Weiss is not actually an elf, but Bladesinger is exclusive to elves, and if Weiss was an elf, high elf would be appropriate and helpful as an Intelligence-based caster).
- Blake: Half Elf Criminal; Arcane Trickster Rogue 10/School of Illusions Wizard 10 (Half Elf is my default for Faunus, as it is the closest to human without being human)
- Yang: Variant Human Soldier; Way of the Four Elements Monk 8/Path of the Zealot Barbarian 12
- Jaune: Variant Human Soldier; Oath of the Crown Paladin 17/Battle Master Fighter 3
- Nora: Variant Human Urchin; Storm Herald (Sea) Barbarian 14/Fighter 1/Storm Sorcerer 5
- Pyrrha: Variant Human Gladiator; Battle Master Fighter 11/School of Abjuration Wizard 9
- Ren: Variant Human Urchin; Way of the Shadow Monk 17/Twilight Domain Cleric 3
- Sun: Half-Elf Far Traveler; Way of the Drunken Master Monk 17/Trickster Domain Cleric 3
- Neo: Changling Criminal; Arcane Trickster Rogue 13/School of Illusions Wizard 7
- Cinder: Variant Human Charlatan; Pyromancy Sorcerer 15/Hexblade Warlock 5
- Penny: Skirmisher Warforged Folk Hero; Battle Master Fighter 9/Divine Soul Sorcerer 11
- Velvet: Half-Elf Soldier; Battle Master Fighter 15/Hexblade Warlock 5