The thing that irks me is that it's the uneven enforcement. Look at this for example https://www.youtube.com/watch?v=F5MdZW1Ennw&t=1s

This was back when SMN had pets. Titan could tank ramuh ex without having to worry about doing the orbs to survive the tank buster. You did have to be careful about aggro management though. Then in one week after this was discovered, we got this. https://forum.square-enix.com/ffxiv/...=1#post2267548

An issue in “The Striking Tree (Hard)” and “The Striking Tree (Extreme)”, wherein the damage taken by pets was abnormally low.
From this, it was pretty clear that they didn't like that Ramuh EX was cleared without tanks.

So I wouldn't be surprised if they updated FRU to where you couldn't simply cancel out P1's tbs.