the problem with enmity is that it forces a tank role in fights where that is completely redundant. Going from tanks having to keep the boss and adds away from the party to just hitting a striking dummy is quite the change of pace. The only way they can necessitate tank roles without forcing enmity as a gameplay quirk is to just make all raidwides into wild charges. So regardless of who has enmity you will always want the strongest "defense" jobs in the front to protect the party in the back. However this might forces the current heavy mitigation meta into overdrive.

Honestly they've dug themselves into a hole in terms of job design.