Team, not organization. A big team might be 5 pairs. There was no hard rule that everyone had to use the same setup - you'd occasionally see pairs in vim or whatnot - but since you're switching computers and pairs almost every day, you tended to homogenize quickly.

My team standardized on JetBrains. Even if someone is unfamiliar with the IDE, pairing gets them up to speed fast. Humans can learn any dev environment.