Strat.
If you want to be like everyone else take 4-5 archers, 1-2 Gla- 2 con.
Everyone having Ifrit bows Helps A LOT. Everyone having B4b, BB, Raise, Sentinel, Sacred prism + cure /sanguine rite(Helps if you are new to moogle fight) Invig, Keen flurry (for archers) and last is your choice.
Killing moogles, Learn your combos and linking which abilities to which combo. as an archer with ifrit bow it's not hard for you to solo the caster moogles with the use of keen flurry and other buffs. Blackmage, Whm, Thief, Archer are the ones you want dead asap during second phase, the others you can easily kite around with little worry while you burn king. (Yes he will still go immune at times but you will be fine).
Learn to kite, as an archer you can kite and still do good dps, as melee you can't do anything while kiting (we still managed to do it with 4 mrd 1 lnc 1 gla 2 con) Thats really all you do this fight, kill those 4 moogles first > burn boss > clean up rest > profit.
tips. if everyone stacks during the summon before flow, 1 mage sacred + rite = full mp, all melee sacred + heal AFTER for full hp and mages not basically starting fresh.
Glads can aoe flash the group x2 and start kiting while you pick off targets.