It'd be great to have A and B combined, but it could be too much for one player to deal with. At the very least it could take months to complete a campaign (something I quite enjoy, but I suspect many players don't). Of course if it supported multiple players then you could divide each area up for a grand multiplayer game. Either way, there should be more to the strategic element than allocating units/leaders to attacks. I'd like to see some sort of supply and airforce management (if quite abstract) and maybe even dealing with the higher elements of command. I'd also like to see support for more than 2 players.
The tactical side of the game is near perfect so I think the time is ripe for a strategic element to be added.