Run each character seperate in a pug, its a multiboxing nightmare.

if you really, really want to do it then you need to assign seperate keys for movement for each character, have all windows viewable at once, and EITHER use the kiting method (everyone choose green drakes, fly big lazy outside circles while spamming the 1 button that heals/damages) and then run away from orbs during banish phases; OR (MUCH MUCH HARDER) choose a combo like 2 red / 2 bronze / 1 green and do all the right actions (timestop after 10 buffs, switch, tank whelps with reds, heal with greens, etc) and still run away during banish phases.

You have to be crazy good multitasking to do this instance, imo. Its 100x ezier just to take each character in once in heroic (get the regular achievements this way too) while its the daily, find 5 decent pugs, and get it down this way.