For anybody having it rough:
earth boi + ice boi = win
maximize earth boi and spam ice bois to make damage from earth last longer
use ice bois ONLY for their slow, unless you got souls 4 days don't waste time upgrading them.
then add flame bois to certain points, space them out and let their damage cover the map, and spam ice mammoths to apply their slow everywhere.
Pick a nice spot or two for the lightning bois, they (at max level) are pretty good at stopping incoming rushes