The best way that i found to do this is to split up the groups. I have two "fighter" groups and one large ranged ant army. when I got to the part where all the spiders swarm the colony I lost twice. Spent hours getting more jelly thinking this was the issue and still lost on second attempt.
On...
Agreed, UPDATE/LEVEL UP those tiles... you will need it on hard. Generally, I dont even use workers to gather food, i just build a massive war party or two. They stomp the opposition and gather my food. Helps save on resources and gives you a large army faster.
Im not a backer per say. I did buy the early access though. I was a little sceptical at first about the game, but man was I surprised. This game is addicting and extremely fun. :D
Had the game for three days and have already beat everything on hard. Cant wait for you guys to drop more...