I use
Wave 1- 100k Warriors. This wave will clear a small amount of Cavs that is necessary with a low attack hero.
Wave 2: 94k Archers, 3k Pikemen, 3k Swordsmen. Clears Cavalry, Archers, and ~30k Swordsmen
Wave 3: 94k Archers, 2k Warriors, 2k Swordsmen, 2k Pikemen. Clears Swordsmen, and 100k Warriors.
Wave 4: 94k Archers, 2k Warriors, 2k Pikemen, 2k Swordsmen. Clears 330k Warriors.
Wave 5: 94k Archers, 2k Warriors, 2k Pikemen, 2k Swordsmen. Clears 330k Warriors.
Wave 6: 97k Archers, 1k Warriors, 1j Pikemen, 1k Swordsmen.

I have 10 heroes 100lvl witch att >300
all city area i colonized, and no one city has nerby,
I attacked today, 2 hr after server maintenance.