Hands down easiest playthrough is
fighter - uses Masamune
fighter - uses Xcalibur
red mage - uses Sun Sword
red mage - uses Defense

Expensive, but ridiculously easy. Even moderately equipped fighters and red mages will do better than anyone else early on. And late in the game you have the money, plus the best weapons/armor aren't bought. Attack Magic is near worthless in the NES version, unless you use the magic casting items. This gives you 4 characters with healing magic, 4 heavy physical attackers, and 2 with attack magic (that you should never use once you get the items that cast spells).
Mage Staff does Fire 2
Thor's Hammer does Lit 2
Zeus Gauntlet does Lit 2 as well
Black Shirt does Ice 2
Light Axe does Harm 2
White Shirt does Invs 2 (for defense!)
Heal Staff/Helm for Heal

THE JACKEL