I don't know where you are in the game atm, but most of the hard content (aol, eop, gauntlet or even act 6-7 bosses) forces you to bring dedicated champs for most of the fights, and usually you will do better with 2 tries of the champ you brought for the fight, then with whole your team. 1 team revive costs 100 units, 2 singles 80 units. Wich mean single revives are better
Make level 2 single champ revives 20 units. Then you equalize the cost of reviving.