W2 is needed to defend the settler when we go to the copper city. The only tile a barbs can be on next turn if W2 moves 3 is the grass hill 1 of the tile, whereas a barb could be on one of 5 tiles, so moving 3 gives a 1/5 lower chance of running into a barb, the downside is the warrio will probably die unless the barb is a wolf, in which case the warrior only might die. But if we moved the warrior 1, there is still a chance it could die.