We are playing AGoT without any expansions. In the past four games that we've played, the Stark family reigned supreme (in 3 four player games and 1 three player game). We argue that their position alone in the north is the reason for their success, i.e. they can freely expand for a few rounds without encountering the enemy. Also being able to concentrate their forces at one place, the neck. The other families have the option of attacking stark via the sea route, though that never seems appealing and has never happened in our games, except a few assaults on flints finger.
Starks poor house cards doesn't balance out their position. We wonder if trading out Lannisters for the Greyjoys would balance our 4 player game. The Kraken seem to be a natural counter to the Starks, as they'd most likely would start expanding towards Seagard and Flints Finger.
What are your experiences with 4 player games (and 3 player to some extent)? Would the map I found on http://www.boardgamegeek.com/image/427600?size=large make a difference to our game play?