A good balance of STR and DEX will work well here to improve the Swordsman's damage, critical hit rate and evasion. Every class will also want some CON to increase their survivability, while Tanks will favor it the most. Excluding a couple Squire's skills, INT is not needed, as none of the Swordsman classes deal magic damage. Lastly, SPR could have some use if SP recovery is lacking, but it is nowhere near as useful as the other three main stats. The typical Swordsman will rather drink SP potions without moderation.