You mean like this?
I realize I only created 3 regions, and that's certainly not enough. Again, just an example. If I had any forethought, I would have divided the larger central island into 2 or 3 separate divisions (like Europe and Asia are separate player areas in traditional RISK, yet landlocked together, just the same.)
I'd have placed a dividing line along that central mountain ridge, pulled the borders back to the base of the mountains and only allow units to cross via the two passes north and south, and blocked from directly crossing the mountain range. The Northeast and the Southern reaches could be separate regions as well.
I'm getting a better grasp at what you do here.
GP
Edit: forgot to upload the new map... duh!