Before I begin I would to state that I understand that the programming for the mac version of the game is done by Virtual Programming. I would just like to know if buying the mac expansions outside of steam, would make it compatible to play with the base mac game from Steam. Because I would like to buy both Semper Fi and Motherland for both of their critical features however the steam site only lists the windows/PC versions of the expansions, even though you can buy vanilla on mac. Any response would be much appreciated as the current steam sale ends soon in 2 days and I would like to buy HOI 3 on there before it ends.