This sounds more like the issue is the (anti-ToS) 3rd party add-on. FFXIV isn't WoW. Its fights aren't designed with the expectation that people are running DBM (or its FFXIV equivalents). I don't see the issue as healers here; I see it as people using tools that should be getting them banned allowing them to do things that aren't supposed to happen. Your typical player not using those tools isn't going to do the mechanics perfectly (i.e. healers under current design are essential when players aren't cheating).