I think the mission itself is balanced if you know in what order things are going to happen?
The main problem I had with myself was going against my instincts to keep my forces at my nest to defend it, as there were many enemies on the doorstep.
I played it enough to know which groups attack where, allowing me to defend in full force. The thing that has kept me from winning on hard difficulty is ants getting stuck in the allied nest:
I think the player needs to get a headsup to know when and where to defend, as ants are far slower than most enemies and may need more time to travel than enemies need to kill the ally.
Well, I've gone ahead to the other side where the colony is. I killed the beetle larvae traps, when I was going to the Wolf Spiders I and the colony haven't killed yet, a tiger beetle out of nowhere strikes then the whole pack of them strikes goes straight for my colony. I was able to defeat the beetles but yeesh!
Since it hasn't really been said, I do think this level should be easier on the lower difficulties. "Easy" should be more of an accessibility mode, where there's not all too much pressure and you can play with very little optimization.
3.1 and 3.2 could use a similar rework at a later date, as their easy modes took some time and RNG to get through. 3.1 in particular I remember a lot of people who played on easy normally struggled with.