Just some other things to consider.The Bishop and Bard also get Insanity. The Bard covers most of the good Psionic spells.
So you have Alchemy (Ranger/Bishop) and Psionics (Bishop/Bard) covered twice.
Wizardry is covered by Bishop.
Divinty is covered by Bishop.
Given how much is on the Bishop's shoulders, the Bishop should concentrate more on Wizardry and Divinity.
So I would either take a Monk to for melee. Or I would take another Bishop for a more magic heavy party. Either way you get three characters with Insanity.