I'm pretty sure fiend baby spam is enough (it works for me at least), just make sure to place chads whenever they are available to boost your economy
I've tried just about everything but fiend spam (cuz i thought they were too weak lol) but it was just enough through the use of spamming chads, cubes, and brains in front of whales and right before the stonies rush, shoveling babies right before they freeze, and using that extra economy to spam a shit ton of fiends (no mowers used, I already lost most of them from "restarting"). Thanks so much!