Yeah, I kind-of cheated with the purifiers, but that was what I just played so it poured out anyway. Prowlers like the OP were really what I meant. I will say, those void walkers are just crazy. You have to kill two unique units to get them. So if you run with the clone, you survive a-ok. That is insane. I had the computer completely suicide once, trying to kill my void walkers, and they couldn't quite kill both. I wiped their entire army out and they didn't lay a scratch on anything else. Just fantastic.Pretty sure the gold standard for early and cheap but effective is troopers with rail accelerators + nanites/flechettes. Also, trenchers + 2 or 3 random mods you pulled out of a hat
Sounds like you're playing for more what I would consider the "mid game" though, in which case try checking out dvar/amazon echo walkers. I think technically the most optimal units for what you're trying to accomplish here is engulfers + a bunch of defense mods but engulfers is cheating
I'll have to look into the engulfers, as they were nerfed pretty hard. What is your thought with them, as it isn't all that hard to get them with the swarm?