The ideal thing is to make one of your fighter 2 handed fighter, and the other dual wielder.
But in fact, 2-handed is more powerful than -I dont care about it, roleplaying is more enjoyin for me- than dual-wielding. Why?
You hava double chance to hit critical strike
You got extra to hit and damage bonus also -4 speed factor
You dont have -2 to hit penalty
Also all the longswords in this game are almost mediocre
While 2-handeds are amazing
WHat dual-wielding does?
You gain only 1 normal attack and do this attack with your off-hand. (It lets you to hit another 1d8+2 (if magical sword) damage. If dont miss of course
Its meanless to compare them. Give one of your fighters 2 handed. THe other one dual-wield. Cleric shield+hammer.