Back to the moogle fight... you CAN keep most/all moogles on you. The strat I always used (prior to getting 7/7) was this kill order: BLM BRD GLD THF ARC WHM WAR KING. Some groups swap brd and gld, some swap thf and arc, but more or less. The blm will go down so fast its no concern. The Gld can switch targets, but in the second or third slot, its rare he'll actually do so before he goes down. If you have threat on him at the end of memento, you should be fine because he'll put out very little group damage before he's targeted. The arc an pick alternate targets, though he always seems to come back to the person with threat, and can be brought back faster by doing things to him. The WHM can be called away as said, but that will result in a cure and he will come back to you. The king has the true threat reset, and you should hold flash/voke for that.

As a tank, I always sought to build as much threat as possible on each target in phase 1 (taking a break to build tp on the blm since he doesn't matter). At the start of phase two, as soon as you see their enmity bars, their threat tables are live and all actions once again generate hate, as such that is when you want to do things like rampart or try to time a sacred prisim cure to hit teh AF damage (saving whms mana and giving you lots of threat). It is more than possible to have a string of moogles chasing you, and that shouldn't requrie your dps to go slow in phase 1. A cocky bard or blm is there to make it go faster and get done sooner, its your job to keep him alive, not his job to do less damage. I found it fun to do on pld, and hallowed ground makes a great kiting "oh gawd i'm gonna die" tool, though its one off.

Your job in phase 2 is to hold the group's hand. Make a macro that screams about being petrified, make another one that screams about the king resetting and informing your group to kindly move or find out how explosions feel. Keep the king targeted but watch those other threat bars. When viel is up, stack it with outmanouver if you need mp and cure yourself through the gentle hits for some threat, pop off rampart when you can, etc. The key to this fight is getting as much threat in phase 1 as you can. This is true of pld, war, and gld tanks. Also, I found its best to run along the edge of the green ground and not against the wall of the arena. That way your whms can stay dead still in the middle of the arena and you will alwasy be in range. Be sure to tell them this so they don't chase you and get cut down by the mrd.

You're a tank, your PRIMARY JOB is to build enmity. It's actually mostly someone else who has the job of keeping you alive. Yes, you can help them, but your job is to build hate. Do it. In almost every instance in this game, if you have enough threat, you'll live virtually by default. Enemies will die quicker and whms will be able to heal more.