It was realy 'hard' at almost 330% difficulty (next ranged ant cost was 3001 or 3002 food). (But in one of my walls of text, I wrote about freeplay uber mechanics, how to fix it as well as for regular enemies spawnkilling each other.) The only difference is, that enemies are actually attacking you instead of each other.
I've done the same with all enemies available, they've killed each other, I've set up 3 combat groups around 3-5 uber corpses and sent my 2 worker groups to gather them. This is considered cheating for those who like an actual challenge ) No, the way to survive is to set up the game mode for only one type of enemies, so they don't attack each other and they invade your nest, then you set up a gate defense with a group of 'gather only' workers and farm the uber creatures corpses (3000 food) that comes in.
