The lack of skill ups and levels are what is holding me back. But I think I might go like so:
For Doflamingo:
Mihawk/Mihawk
Arlong/Jozu
GP Usopp/Perona
Perona, GP, Mihawk all max skilled. Everyone max level except Jozu. But I ran this last time and had nothing but trouble. I could swap out Mihawks for G3s and put Mihawk in place of Jozu, I guess.
For Enel:
Doflamingo/Doflamingo
Mihawk/Law
Miss Doublefinger/GP Usopp
Law is only level 57 with a skill level of 2, Doublefinger is 37 with a skill of 1, and Doflamingo is level 40 with a skill of two. So I'd look for a skill maxed friend captain, I guess.
Haven't had good luck with the lower-stamina raid tiers, so far as drops go. But I feel like I need to soup these dudes up to make it work reliably.