I'd be interested to see how the Mayfair version handles flag placement/removal. The Phalanx version places control at the end of the turn, the living rules at the end of combat. Which is a huge difference, affecting recruitment in a freshly occupied space.
My copy has arrived today.
Mayfair default basic rule says
"You take control of a box by having at least one of your units in that box at the end of one of your segment"
and basic optional rule #R says
"A player takes control of a box by having at least one unit there at the end of his friendly combat phase instead of at the end of the segment"