Personally I think Bosh is the easiest of the big 3 too replace, assuming Wade can ever be healthy again. There are plenty of bigs who do what he does. Not as efficiently on offense ofcourse, but definetely on defense, in the post and on the boards.
As for his contribution on D, there was a recent Zach Lowe article that describes Bosh's contribution. Basically, the need him because of the way they play D, but they could play a much easier or traditional form D if they replaced him.
it’s fair to wonder if the Heat might be better off swapping Bosh for a sub-elite facsimile and searching for puzzle piece role players on the cheap. Guys like Paul Millsap, Al Horford, David West, and Brandon Bass can hit midrange jumpers at elite rates for a fraction of Bosh’s annual salary. And if the Heat could somehow parlay Bosh (or Wade, really the more tradable guy from Miami’s theoretical perspective) into a legit rim protector and rebounder, they might be able to dial back the frantic nature of their hyper-aggressive defense a bit. That defense works very well on balance. The Heat just repeated as champions, and their flying athleticism smothered San Antonio’s precision passing attack in Miami’s four championship wins.
But that defense is also exhausting. The Heat in all three of their playoff runs have shown off-and-on signs of serious slippage in executing that defense — against Dallas in 2011, Boston last season, and both the Pacers and Spurs this season. Those teams are all very good, but Indiana this season was a mediocre offensive team, and the 2011-12 Celtics were one of the half-dozen worst scoring teams in the league. All of those teams deserve credit for periodically slicing up Miami’s high-risk defense, but the film shows a lot of very basic errors an amped-up Miami team doesn’t typically make — fatal ball-watching, miscommunication, lazy rotations, and traps that lack the Heat’s normal oomph. James is 28, Bosh is 29, and Wade is 31 with annual late-season injury issues. Finding a way to dial back the hyperactivity might be a good idea, and adding a more traditional paint presence would allow them to do that.Miami's D is good (9th overall) but not great, and will likely remain that way if Bosh is stuck at the C. Personally I believe everything is derived from how amazing Lebron is, not only offensively but defensively. He is simply so intelligent and verstatile. Strong and quick. How many players in this league can responsible for covering David West then Paul George? Can cover Tony Parker while offer rim protection from Tim Duncan and other bigs?Everything will be fine as long as the world’s best player is in his prime, and that half-sentence works as both a defense for keeping the team together and a potential argument for at least thinking about trading Wade or Bosh as a way of maximizing available salary. If LeBron is this good, do they need two other stars — especially when the reliance on a nontraditional big man, Bosh, has shaped the helter-skelter style in which the Heat play defense?
All that said, Bosh on the Raps? Wrong direction as far as I'm concerned, but assuming a team thats not looking to tank - if it was Bargs + Derozan for Bosh? I'd say go for it. (not likely to happen ofcourse)