Honestly, best answer to combat boredom is to up the difficulty. The lower ones are... dull. Too simple, too easy. Cant tolerate them myself.
That being said, the Hydral tech ones could do with some sort of upgrade. The golems are pretty easy (and this being on Misery) and the missile turrets are no threat. Missiles are only a problem when there's tons of bullets flying in every direction with high density, which just isnt the case in that mission type.
Nah, I have no problem with combat boredom. The difficulty is fine with that. I'm talking about the strategic difficulty.