As far as terrain goes, you localize any part of a map and it could look like rhine in AH does. Getting any map that has a similar shape of Russia and Germany and the Baltic area would be a 1/1000th replica, instead of a 1:1 (like say BOB04 is).
As long as the distances each mission flies are well laid out, the start fields, etc, the action will flow from there. As long as it has the right look (i.e. not sahara desert for Eastern Front) and the action will take care of it.
It's very easy to accept a different map as long as you view it as only a very localized battle map (NOT the entire continent).
IMO the micro-view look of the terrain goes better toward immersion and illusion than the vague out-of-scale outlines of the shorelines AROUND the map.