Thread:Linathan/@comment-32851607-20170813233538/@comment-26140304-20170814022558

There isn't much of a tier list to go off of, since squad compositions are all dependent on the buffs you take. Omni units come with different structures of buffs, so the squad will have to build around that. There really isn't a "best" squad to work around with in content.

You don't have a lot of units to work around with, so I highly suggest expanding that unit list with more units from rare summon. For now, here are the following recommendations for the objectives you're requesting.

Arena Questing & Raids
 * Camilla lead, Zelnite, Mariletta, Hugh, Elza
 * Shida lead, Zeleste, Mariletta, Shera, Zelnite, Regil friend

As for your UoC, Regil, Shion, and Cleria are some of the most popular choices as they carry some of the best combination of buffs in the game; though, I highly recommend playing through the game and collecting more units so you can further narrow that list down to who you really want.