[Kambei is considering the farmer's offer]
Kambei Shimada: It's impossible.
Katsushiro: Sir! Why not arm them with...?
Kambei Shimada: I thought of that, too.
Katsushiro: But sir.
Kambei Shimada: [pointedly] This would not be a game. A band of forty bandits! Two or three "samurai" could accomplish nothing. Defense is harder than offense. Mountains in the back of the village?
Kambei Shimada: Can horses get over them?
Kambei Shimada: Fields in front. The village is wide open to horsemen... until the fields are flooded. One guard for each direction takes four. Two more as a reserve. You'll need at least... seven, including me.