Every so often, you get a card that allows you to place additional armies on the board.
It can be either a set amount (the same every time you get the card) or variable, increasing when more territories are held or as the game gets into the later turns.
I like Riyamitie's idea, this would be very useful in 1v1 games. But I think that it might be a bit OP if you only start in 3 places like in the strategic 1v1 template.
How about a card that would let you move armies from one place to another, over any distance. that'd be awesome and very useful if you've a large stack.