Idatu is easy
I played Idatu - never lost a battle, never lost my hero. For the first few levels I just produced a lot of pawns or protos and sent them to the enemy base, and did a lot of damage to the base with my hero. I used the laser weapon which is good for luring. Then once I got to the level with Apoly (the big long range tank) I just made a lot of Apoly and set them to defend. I used my hero to lure big enemies away from the enemy base to my own base to kill them, as I increased my number of Apolys. (Note that you can just make the maximum number of Mines at the start for fastest resource getting).
Then when I had "enough" Apolys (like 34-60 population depending on the level), I set them all to attack. They wipe out everything with their extreme range, nothing stops them - on the last 3 levels I didn't lose a single unit.