Is there some unspoken rule to not use Esuna/Leech?

[Lemuria]

The problem here is that it's rarely just status. At the very least, you're in a position to take a sizable amount of damage when you get hit by it. The is especially true if there is more than one status condition/stacked status.

Most skills which inflict a status effect are low damage hits. The few that aren't are heavily telegraphed and are intended to be avoided, stunned or silenced. Obviously, you play things by ear and adjust your tactics to the situation. Heals should always take first priority, but I'm not dropping Cleric's just for a weak poison or paralysis if the tank doesn't actually need any heals.

A Pacified tank (WAR) cannot grab adds, nor can they tank swap for mechanics that necessitate it. I'll give you one guess as to who those adds are going to make a run for though while your warriors are asking for that esuna/leeches.

Sorry, but if you're ever in that situation then the Tank has already messed up. Firstly by not timing their berserk better, and secondly by not using Flash.

Besides which, if your team is weak enough to be wiped in 5 seconds of aggro you have far greater problems than pacify.