Quote Originally Posted by Provengreil View Post
No matter how you slice it, mixing tiers by a difference of more than 2 tends to create problems. even 2 can be a stretch. so if the fighter's involved, it's bad form to take the wizard, pretty much(this assumes the other party members are, say, a monk and a rogue. it's the fighter's fault if the others are a favored soul and a druid, or something such as that.)
Maybe for you, but not for everyone. My group has been playing for 10 years. Fighters, barbarians, and monks have been mingling with clerics, sorcerers, and wizards the whole time without any problem whatsoever, including one campaign with a Divine Metamagic Persistent Spell cleric when Persistent Spell was only +4 levels.