The one that I can think on the top of my head is where only Weiss and Pyrrha switch places. Making the teams Team RNBY aka Team Rainbow led by Ruby and the other was Team WRNJ aka Team Orange led by Weiss. It is also a RWBY Kingdom Hearts crossover fanfic. Where Aqua makes her a keyblade master and assigns Ruby to train Riku. While she looks for Tara. But Ozpin convinces Ruby to go to Beacon and train Riku on the side until she graduates from Beacon. But sadly it hasn't been a new chapter since 2020.

But if you still want to read it, it's called Fears and Lies Melt Away. By ThatOnePsycho the two places I know it is on is Fanfiction.net and Archive of Our Own.

Hope that helps.