'Red Star over Europe' cross compatible with Vietnam AND TOD

[Embis]

That's because the scenario uses a map that is not included with the mod, "Tagab.map".
I'm guessing it comes with Soviet-Afghan war.

Yep, That's an original SAW map.

So I guess that needs to be an additional caveat to cross compatibility: any scenarios in a mod which use maps native to the base game wont work in any other base game. 

In those cases one would need to buy the original base game to get the map.

... but would that really be so bad? .. these are damn fine games!