Is there anywhere I can check to see where an enemy's "head" is? I'm having a hard time figuring out where the archon's or an amalgam demolyst's headshot zone is.
The weird ones are moas and a couple of the infested units. Moa units the "head" is sort of between the legs (the backpack sometimes also counts). For infested chargers it's the little round nub between the front legs. Nearly everything else is pretty much where you'd think a head would be.
For the archons specifically I'm not actually sure they have a headshot zone, they've got all kinds of mechanics and damage reductions/protections. E.G. they're immune to armor strip. It would not surprise me in the least if they have no headshot zone and are immune to weak point generating abilities like Helios or Sonar.
Archons definitely have heads, one of the ways to oneshot them relies on Ivara's headshot bonus. I think both their actual head and their archon shard counts as a headshot, but I'm not entirely sure on that part.