HereForTheBeer: It's a "take your time" RTS. In some regards you can almost look at it like a puzzle game - "how do I crack this nut?"
Once you get through some scenarios, you'll get an idea of how the enemy units are placed. And then artillery does much of the heavy lifting.
Aviation is a bit tricky at first, but the AI uses it a certain way so it's not too difficult to counteract once you know the patterns; I believe one of those threads discusses that.
They also discuss using officers as scouts, in the event you lose your snipers.
So learn aviation, artillery, and scouting to get you through a lot of the game. Then take note of how the enemy is typically deployed; for instance, if there is a little hillock alongside the road, expect to find anti-armor weapons in place there - and then bombard them with arty and try to approach from behind to mop up.
Oh, and get the hang of repairs / reinforcements. Very important part of the game.
Alright, thanks. I'm on a mission now where I don't seem to have artillery, like the 4th mission on the allied campaign. It just seems like I send troops and tanks to attack and they're immediately destroyed because the enemy doesn't come after me, I have to go to them. Practice is the best medicine I suppose. I'll keep at it!