I farmed Grendel again recently because I needed the subsume ability and both times I used the hildryn method and it still worked.

It is possible to skip adding elemental ward, just will be killing things a bit slower. Important now if the player is new, I think I saw this week duviri curcuit was hildryn and could get the haven augment mod with it.

I did bring a hammer this time in anticipation of eximus units being too tough to kill and some were. I don't remember being in danger of getting killed though.

But bloody hell this mission can be a bore at 20 min survival or the 800 cryotic excavation that barely spawns the right mobs to charge the excavator.