You're assuming that Valve is trying to make hay somehow by promoting this game, but I wonder if the game's placement is simply a result of a spike in sales by

You're assuming that Valve is trying to make hay somehow by promoting this game, but I wonder if the game's placement is simply a result of a spike in sales by users who can't purchase it on the Mac App Store. I'm guessing it wouldn't take many purchases for the store's logic to pick up a historical strategy game as a trending seller.