To complete levels, with maximum technology you are guaranteed success if you train loads of Snipers/Crazy Harrys, these mow down the enemy before they have a chance of attacking. They are more effective if placed lines or arch-shaped around where enemy appears, this ensures all the men get an opportunity to fire and the enemy has to attack each Sniper/Crazy Harry individually.

In many levels the enemy has unguarded or poorly guarded derricks, take a group quickly, avoiding trouble, and destroy the derrick. Sometimes they are not replaced and even when they are they considerably hinder the enemy, their future attacks will be less powerful.