I like a variation of #3. Don't limit the level that can be attained in the early years, but make it take longer. Early in the war units did not dig-in unless they planned to be there for awhile, whereas later in the war, units could (and often did) throw up formidable works almost overnight.

I ordered my game Monday night and it cost me $49 and some change. Download was a little slow, but 4 hours later I had the game installed and played through the tutorials. So far it looks to be an excellent game!