Part of the experience that needs to be gained by young players is what 'playoff basketball' really is/means. Sometimes it means that Jordan rules are amplified, like it or not the refs are human and expect Lebron to do that extraordinary thing and officiate with that expectation in their minds eye. So, that slight bump by a defender is going to be called when Lebron's shot doesn't drop and the opposite is true when he is defending. That is a reality which is present and isn't blaming the refs - it is just life. The players need to learn that and live with it psychologically.
Similarly, playoff basketball means that when players are cutting through screens they are going to get held, pawed at, tugged, pushed, etc. The same holds true on inbound plays when they are trying to get open. Brown especially went through that in game 3 when Cleveland sought to deny him the ball early to prevent him from getting started. He was held, pawed, anything to disrupt the timing of the actions designed to get him the ball or get him to comfort locations. Tatum seems to be engaging in the same (call it hand fighting?) all over the court all series and doesn't have the same bulk to fend it off as much. These kinds of things are also part of playoff life, and they need to learn to push through it, or fend it off, or anticipate it to avoid it. Perhaps by scheme, perhaps by Brad having conversations with the refs, perhaps by change in home court - somehow it has to be dealt with.
This doesn't count the reality of the scheming changes that happen game to game in the playoffs which isn't present in the regular season. This doesn't count the mental expectations, pressures, additional press, additional fan intensity,external distractions of family/friends in attendance, etc. It is hard to win in the playoffs in most sports, I try my best to not lose sight of that when watching these young guys/team playing this 3rd round in the playoffs. I guess I'm trying to find a way to take a breath and enjoy the enormity of what they are doing earlier in the growth cycle than I had personally expected it.
That all said, I believe they can still pull this off - it was never destined to be a cake walk even after the hype of the first 2 games.