The general consensus on weapon style is:
two-weapon style is useless unless you spend 3 slots on it.
Its best if your off-hand weapon provides bonuses other than attack-related, because your off-hand attacks infrequently (so Da'kkons blade is a good fit for your off-hand since you get an AC bonus and spells).
Crom Fayer is a great off-hand weapon with its STR modification.
Sword and Shield style is useless, so even if you decide to use this config, don't spend slots on it. Shields can be nice, but I prefer to cast buff spells to improve AC, rather than cripple my fighters by equipping shields. You also can't equip bows or crossbows with a shield.
Two-Handed style is nice for pure power. At least one of your fighter's should use this. More criticals, more damage, more carnage
