I just want to add into this, in my personal opinion, auto combat completely sucks. Not really just in this game, literally every game where there's an auto-combat function it makes incredibly inane decisions way too often. Thing is, I don't have that impacting my opinion of CoC2, because the last time I played without having manual combat as being always on was, I would guess, March 30, 2019 (When manual combat was put into the public patch). I'm fairly certain that that function getting added was the deciding factor between me hating or loving this game. Management of the party's threat goes fine, especially since the shield stance which Warriors and Atugia have got buffed at some point to automatically generate threat, and you can actually make proper tactical choices rather than hoping Cait remembers to heal you when you're at one health.
I personally feel, maybe the options aren't that well highlighted: Despite the per-combat toggle being right on the UI when in combat, with a tooltip, there's no in-tutorial moment where it says "if you want, you can change between your companions fighting automatically, your party fighting automatically, or your party fighting manually" or something like that. It's not even mentioned in the Combat Basics section in the journal, despite having a major impact on how you play the game. In the options menu, it's all the way near the bottom. It's entirely possible to not even realize it exists or what it does.
Also, in the threat section of Combat Basics, while it does state "high-damage hits or high-healing abilities will generate threat most quickly," there's no mention of healing generating double the threat (though now it makes sense why Atugia also has healing abilities). So, since you say that healing, even if it doesn't actually heal, generates double the threat, Bolstering Dance is effectively generating more per-turn threat than Guarded Stance, as BD generally heals 10 resolve per turn to all allies, and GS generates 30 threat per turn (aside from the increase to threat from abilities).