@Cernel Yes, as long as the first territory moved into was not another mountain territory. If the first move were to enter the mountain territory the cost would be 2 and the armor would not be able to continue movement.
I understand what you are saying, my suggestion is just an option for the map makers. If the mountain territory is set to '2' and not '2-1' then the armor would only be able to enter as its only move.
Hope this help explain my suggestion.