Handsome devil huh?
I play on the standard 36" x 30" battlefield and I agree that things can get a bit cramped, but once the battle commences you can use the 5" on each flank that was restricted during setup, which means you have some room to try to outmaneuver your opponent.
Also note the rules for a Larger Playing Area in Battleground: Kingdoms:
The Battleground: Kingdoms Rules wrote:
Larger Playing Area
In the green rounds of Battleground Kingdoms, the board can become congested. To alleviate this, add 3.5" to each side of the board, and extend each Deployment Zone by 3.5" in each direction. Leave Terrain where it was, so that if a piece of Terrain is shown on the Map Card as being right up against the edge of the board, it will now have a gap of 3.5" between itself and the board edge.
The "Green Rounds" start at about 2500 Muster Points.