Experienced players can Wall Jump to either of the holes, while the rest should wait for the quicker shaman to build a bridge.
Attempting to kill the other shaman is dangerous, because the spawn point is the same for both mice and shamans. You should try building as fast as possible to get more mice into your own hole. He can make a Spirit on left on the center of the plank to throw the mice into the hole. If the shaman has Spring he can put one on his/her side of the pit before the other shaman has time to react.