1) I disagree that Brand plays 'much better defense'. ce some might have missed.
Brand plays elite-level defense.
Bosh plays Ru Paul level defense.
Elite defense > Ru Paul defense
Thus, Brand = much better than Bosh
In terms of your other point, I think you basically have it right. If you replaced Bosh with Brand on the Heat, you'd be getting a fairly close facsimile.
This is has been bugging me all draft, so let's air out this 'Ru Paul' thing.
Bosh is not on KG's level on defense, but lets stop pretending he is a net negative there or something. The man had one really bad game against Shaq. Playing Shaq just isn't his strong suit. It isn't Elton Brand's strong suit either. Bosh isn't the toughest guy in the league, but neither is Pau Gasol, but that doesn't mean he is a bad defender. Serge Ibaka wouldn't have faired better, neither woud Brand. Well actually Brand might have, he's stronger.
The point here is that unless I'm facing Bynum or Dwight Howard, I don't think there are many bigs left in the NBA where Boshs defense isn't a plus. And factor in his extremely versatile offensive game, he's a lot more than just 'Ru Paul'.
Now back to the record at hand, how does Trevor Ariza fair defending Lebron James, and is it good enough to stick Boozer on Jeff 'no heart' Green?