For starters, they are not among the best at their respective positions any longer. I am not sure how any players you could locate who are better than Wade and Deng at their respective positions, but both players are being leapfrogged by younger players around the league and Bosh's decline has been several years in progress. Wade, with the greatest player of our generation playing by his side, attempted a career-low in field goals per game this past season, yet drilled them at a high rate. Even though he was rested and shooting at a high percentage, he wasn't shooting much, despite having the space to create often. Without LeBron, those shot attempts go up, and that shooting percentage takes a dip.
We all saw Deng last season. He looked like a guy who was beat up from injuries and excessive minutes under Thibs. Bosh could have somewhat of a bounce-back season, but what Bosh are we going to see? Do we expect to see Bosh back on the block more often? I just don't see it.
We are talking about a team that -- come playoff time -- will have six key players (Wade, Bosh, Deng, Granger, Birdman and Haslem) 30 years old or older. That's six rotational players who are past their prime and / or giant injury risks. The sub-30 roster consists of a few okay players and a collection of stiffs (Brown, Chalmers, Cole, Ennis, McRoberts, Justin Hamilton, Shabazz, Tyler Johnson, Reggie and Shawne Williams). The team's best players are rapidly aging and past their prime. The young players are either not talented enough or experienced enough.
I get that you included the caveat of Wade being healthy, but even if Wade still gets as healthy as he can possibly get, he's not even remotely close to the same player he once was. The last time he looked even remotely close to the old Wade was during the 2011-12 campaign. Unless he's suddenly expanded his jump shot, he's not going to be that great this year.
I know you made one single post, so perhaps I am taking my frustration on this subject out on you but you aren't the only person on here who has stated that the Cavs need to look out for Miami. My response is that they don't need to worry about the Heat any more than they need to worry about the Hornets or the Wizards or the Raptors. We all saw the Heat jump on LeBron's back in the playoffs over the last two years and the only thing I could think of while watching was, "Wow this is reminiscent of the 2009 and 2010 Cavs playoff teams". Now, without him, the Heat will finish somewhere between 6 and 9 in the East. I can't see Miami finishing ahead of Cleveland, Chicago, Washington, Toronto or Charlotte. Not with the top-to-bottom rosters these teams have compiled.