Brad is going to be second guessed by most fans (including me) until he wins it all. Even if he can get to the finals, that will buy him some equity for a few seasons.
This season is frustrating primarily because the opportunity is there to get to the finals that is not at all unrealistic, especially given that the Heat took care of our biggest nemesis, the Bucks. The Sixers were very undermanned, so that was a first round gift. The Raptors sans Kawhi were very beatable, and credit to Brad for getting that done, without Gordon no less.
This Heat series is where I feel Brad has lacked a certain level of creativeness. When things aren't working, he tends to say that it is failure of execution, staying in the moment, etc. But sometimes you just need to shake things up. Maybe he did not feel the pressure to do so until now. Does he now? I don't know, we will see.
He has that capability. See what he did when we were down 2-0 vs Bulls a few years back. Gerald Green inserted as a starter, and it really energized us.