How to make voicebanks sound like multiple people singing at once?

Hey everyone! I've been working on a cover of Hearts2Hearts' "RUDE!" using SynthV for myself, but I'm having some issues with the chorus.

In the original song, it sounds like multiple voices singing together, like, they're all on the same note, but you can still hear that it's a group of voices. I've tried recreating that in SynthV, but it ends up clashing and doesn't sound very pleasant.

I've tried with the choir function and also editing in Reaper, but it still comes out more like an oversaturated single voice rather than a group.

Does anyone know any tricks to do that effect? Or maybe some mixing tips in Reaper to make it sound fuller?

Thanks a lot!