Tank appears in some inappropriate position

[deltamaster]

There is a very narrow path for tanks to get to the west at the south of the map.
When several tanks try to gather there, they try to expand and avoid covering each other. However, they do not always move towards the correct direction, that is, some of them will move into the water. Once in water, they cannot be moved any more.

[MPW1412]

The thanks even stuck on mountains :)