I'll also have Synastry, so I can put it on the tank and heal both him and the prey target at the same time - I was doing 2 lustrates on the prey and 1 on the tank, and with Synastry I can just use two big heals on the prey target and the tank will get healed by the same amount as he was when I was SCH, with less resources. Healing with Helios requires less MP than healing with ET+Succor and Benefic II costs less MP than ET+Adlo. It's basically an easier way to do the same thing, honestly, and this happens because of the difference between the two jobs internal mechanics. I'm pretty sure this isn't the best strategy while playing SCH, but it was what my WHM partner felt most comfortable with, and I'm going to be able to handle it better as AST – or at least some parts of it.