jazz, I think the point is that (OTOH) you don't say "the team are us"?

No, I wouldn't say that either. This is obviously a case, and there are many more, in which a plural noun mysteriously becomes a singular noun. It's an act of unification. "We are a team" reinforces the maxim "There is no 'I' in 'team'."

P.S. What's this new acronym of yours (OTOH)?