I'm assuming this would be brayflox HM speed run, correct? since there's blm & brd there.

Tanking's not my main job, and PLD's especially kinda a bit tricky compared with WAR for maintaining aggro for large mob group. The key is to spam flash several times, like 2-3 times for opener, then Circle of Scorn, then spam several flash again but make sure not draining your MP all the way, about 1-2 flash should be enough, and then rotate your Rage of Halone combo on each mobs. Don't forget to keep using Circle of Scorn when it's cooldown are over and maybe slip another flash between if you recovered a bit MP for it. This would become easy once you're accustomed to it. ^^

When I'm in rush of needing quick myths, I usually tanking those.