This change does not make any other team more effective in any way relative to the actual damage done. The only change is relative to what a JTR team can do, and that is frankly irrelevant. While you have correctly identified that RJT teams being so dominant is the big issue, you have incorrectly identified the actual reasons behind it.
Expose damage is not the issue with RJT teams being the best, but rather the irresistible aspect of it. Teams are neutered not because they can't compete with percentage health mechanics (some of them rely on it, e.g. Vader), but because the high tenacity prevents them from doing anything.
This raid disallows debuffs because of tenacity, disallows buffs because the boss steals them and recover protection, disallows bonus attacks because they get defense down and lose protection or getting dazed or shocked, disallows healing by the constant barrage of damage. It's fine if a few of these strategies are restricted, but not all of them at the same time.
I would be surprised if even some of the top guilds can complete the raid again.
