The thing about AoE vs focus fire is, you generally want to AoE unless your tanks can't take the heat, or you need certain enemies dead ASAP. AoE does more total DPS than focus fire, in many cases significantly, so if your tanks can handle it, go for it.

As a BLM who used to religiously Sleep mobs and focus fire, and who is now in the last remnants of end-game, I'll AoE almost any time there are 3 or more enemies. This is easier when you're over-geared, but in all honesty, there's not much reason to go for CC in FFXIV so far, unless the players are bad or severely under-geared. In 99% of situations, your tank won't die from even 4 mobs beating on him if he's competent, so CC is just a waste of DPS currently.