Well coached or not, this Heat team has the capacity to be not only beaten but humiliated. Less than 12 months after upsetting the Bucks in the bubble, Milwaukee swept them in round 1 in 2021, by an average of 20.5 points per game. Herro and Bam as lead scorers are not great at creating their own shots (their TS %s would be dead last if combined with Boston's 8 man rotation), and losing Butler/Rozier makes them significantly weaker on both ends.
Their only path to victory (aside from injury to multiple Celtics' starters) is to go red hot from 3, hope Boston goes ice cold, get physical on every drive and hope the refs start letting them go. That's basically what happened last spring, and the series went 7 games in part because Butler went off in the 4th quarter in games 1 and 2 (and almost won it for then in game 6). Taking a step back and looking with from a neutral eye, this series shouldn't be competitive (not earlier in this thread, but the Celtics are nearly even odds to sweep the series). I expect the individual games to be closer than that, but it's really hard to imagine a way that this goes more than 5 games.