You're basically right.
As far as just getting all the prizes here, you probably don't need to fight demons whose levels are so high that you need +HP to avoid dying instantly to an overdrive. So in that context, you probably want to go with something like what sanahtlig suggested.

But, be prepared to adapt accordingly if your union is at a point where the bulk of your members need the turns but are struggling to survive past 2-3 overdrives, and that you're not on pace to get all the rewards.