You will definitely need to plan things out with your Astro. Having the SCH solo heal after Photon is not very efficient because they have pretty limited burst AOE healing (Emergency + Succor + Indom). Relying on an Adlo spam hoping for a crit because your AST doesn't want to precast a Helios is terrible and is time that you could be DPSing not to mention Adlo is very MP expensive.
I'm not really sure what order my AST does their heals, but I'm sure it's probably Aspected Helios precasted to go off as Photon Hits followed by a Helios. That combined with your Indom and maybe Sacred Soil (depending on how many stacks your group has accumulated) should be plenty to keep everyone healthy. If your Adlo typically falls off before Whirlwind then you can also Succor after Photon goes off for that extra bit of redundancy.