Just to continue on about how bad cover is, Intervention is objectively better.

I don't now if Cover takes into PLD's innate 20% damage reduction (so, if an attack was targeting a healer for 10K, it would only do 8K to the PLD), however, if you had instead used Intervention, that is base 10% damage reduction, plus another 10% from Knight's Resolve plus the 1000 potency Regen from Knight's Benediction.

Sure, you could increase Cover's effectiveness by using Rampart or Sentinel, but they do also buff Intervention, plus, depending on timing, you could lose out on using them for a tank buster.

As for the after healing, the healer has to either heal you as the tank, or the one the attack was directed against, it makes no difference.

Even then, any attack directed at another party member is not going to be designed to kill them to the pint you have to use Cover, other tanks don't have that and you cannot force a certain job to be required.

Overall, with Intervention, Cover is redundant. If they want Cover to stay, it has to be strictly better than Intervention. This would then lead to a disparity where Cover is better for the odd mechanic and Intervention is used for (shared) Tank Busters.

I suppose, in theory, you could cover someone who is about to die to the next mechanic, but that is a very niche use that Intervention might not be able to save them from but is this one niche enough to keep Cover?