You may try upping the AI. The AI has a hard time dealing with one crucial element of the map, it does not use sailing.
When playing against the AI, here are the nations to play from easiest to hardest.
Easiest Vanheim
Easy Niefelheim, Ctis
Hardest Ulm
In multiplayer games the above should not hold true because Human players will take advantage of certain elements of the map that the AI cannot.
EDIT: Wanted to add, thanks for trying the map and the great feedback
