I don't think this is really a great deal for either team.
The Celtics would be getting a player who is going to need to be paid in the off season. We aren't sure how good Barnes is going to be and Crowder is on an absolute bargain contract.
The Warriors are having a historic season, they would be foolish to mess with anything.
As far as comparing the Warriors to other great teams, you have to realize the differences in rules from year to year. The Jordan Bulls were great, but if they were playing today they would be called for hand checking on every possession, with the way the Warriors double team and recover they could really give Jordan problems (they way W's double team the ball and recover they would consistently be called for illegal defense in the Jordan Bull's days).
I'd still like to go after Barnes in the off season though.