Advice for a beginner against AI ?

Hi, I've played a few skirmish rounds against the AI and they usually start off well but the longer it goes the harder it becomes.

This game requires quite a bit of micro managment for every single soldier to maximize effectivness and reduce casualties. But the longer a game goes and the more Points you score the more Units you will have at your disposal and the micro managment becomes unmanagable for me. Especially since the AI also gets more Units and can just Issue commands for their soldiers simultaneously, while I have to issue orders for soldiers one after another.

This usually leads to me not being able to micromanage fast enough to give orders to an infantry squad to spread out a little and a single grenades or Machine gun wipes them out easily, or I don't notice that my vehicles and tanks are being shot at.

I hope you guys understand what I mean and could me give a little advice