Tank stances would work if aggro was disabled in off stance, thus requiring someone to stay in tank stance in order to hold aggro. If provoke or shirk didn't work when you are in an off stance that would potentially fix things but raid design would still need to be taken into consideration. I think o4s is probably a good example where enmity resets after grand cross required the tanks to be top 2 enmity asap or the mechanic might target a party member. Now if we apply the same mechanics but if one of the tanks were in Deliverance, Darkside, or Sword Oath, they would not get aggro and potentially kill a party member.

Ultimately Tanking has lost any sense of actual tanking and all we are is just a weaker dps with more defense. To the people who said tanking was just tank stance > one enmity combo > off tank stance. Guess what you do now. Regardless of tank stance enmity has been buffed so insanely high that it is possible to keep hate and we even have less combos so literally all you are doing is spamming an enmity combo. No reward for going into off stance and risking higher damage for potentially losing aggro.