oftentimes we talk about the importance of a small, core team in localization for the sake of consistency, and that's REALLY important, but you can argue more people also means more creative language in a work on the whole. phrases i use aren't what another editor would use.
sometimes i proof others' works and i see a phrase or word i'd never think to use--some i didn't even know existed!--and it's really cool. it keeps the text lively and fresh throughout, so i like that about working with a team.
making sure the voice is consistent is important, but a new word or phrase here and there isn't going to throw off the overall voice. i don't see the harm in that at all!