First, start a new war party, selecting what ever heroes you want and then add all five swordsmen.

Second, use a hex editor to edit the Swordsman definition in the save game and change the following items to the values shown, once that is done you can return to the game and load the savegame and sell the Swordsmen back for 65k each in gold.

Here are the items to look for and the value to change it to;

Cost = 01
Points = 01
Initial CP = 0
HP = 001
DR = 01
Evade = 01
BDMele1 = 10
Hit1 = 10
MaxHit = 01
MaxBD = 01