Slitherine

I'm new to the game, I've played Panzer General but first time playing Panzer Corp, I've been throught Poland, France, Norway, and England, now I'm Heading to Moscow, I've received no SE units. How come? Just bought Mega Pack is this unit still there?

The SE units should still be there. You might have gotten very unlucky, they are randomly given at the start of a scenario, and you can only have a couple. You are not playing with a modded game perhaps?

It's called bad luck, in my first playthrough of PzC I only got 1 or 2 very late.

To get an SE unit. Save your game after you capture the last victory hex. Finish the scenario and if you don't get one reload and keep reloading until you get one. Have a couple of units that haven't moved so as to change the scenario checksum which alters the probably of generating a SE unit

Well I got one heading into America. Tank Killer.