Strategically, you should start putting your units late on the track, so that any new units get a chance to train, but then you have to wait for the enemies longer. A game so slowly paced you sacrifice strategy out of boredom is kind of failed...
The commands don't make any sense... I understand what to use retreat, drop and push forward, but why on earth is there two more commands? Combine them to make "retreat", "stay put and take cover" and "go forward and attack anything that moves". That would make things a lot more simple and clean.