[Battlegrounder Free Mode WG] Avoid Tunnels

I tried to create a path that runs in middle and zerg in Warsong Gulch, but fails somehow and tries to climb up to the ress point, so I use it in free mode. The problem is the path choice that the robot always take: most of times it prefers going into tunnels and do the slowest path, is there a way to block the tunnel path and let the bot zerg in the middle?