I don’t know how feasible this will be from a programming perspective so feel free to brush this aside if it would require an overhaul of any of the current balance systems as I thoroughly enjoy how Last Epoch currently plays.
That said I do feel like the enemies fall into one of two categories: run up close and smash face into player until either they or you die; or stand further back and shoot at the player hoping to kill them before they get too close. It makes me feel like I am the bullet sponge/dps check in the enemies’ adventures. If, however, there was a mechanic in which some enemies would protect others, or if they had abilities that allowed them to block escape, it would allow for a bit more variety in enemy encounters without the need to add new enemies. The mindset I’m getting it is asking the player to prioritise their targets during engagements. The shades that necromancer enemies can summon have a bit of this in that they stop being a threat after the necromancer is killed; but with so many enemies on the screen its difficult to tell which necromancer has shade thralls and which is going to get facerolled before managing to summon anything.
Admittedly this is coming from someone that has only really played sentinel and summoner necromancer so it may feel different for other characters (or players).