Another option: Use only the warrior class and turn the other two classes into feats. How to do this? First, add four (yes four!) feats at first level to the warrior, but take his hit die down a step, and take away his free medium armor proficiency. And reduce his BAB to the spellcaster level.
Additional feats include:
a) Better Skills: Add 2 class skills. Add 2 points/lvel from now on, x4 if taken at first level. Can be taken a total of three times.
b) Better HD - take HD up a step, can be taken multiple times, can only be taken at 1st level, max HD d12,
c) Better Saves (get one more "good" save), can be taken twice, can only be taken at 1st level.
d) Spell casting ability. Choose Divine or Arcane on taking this feat. Has ability to cast spells as spell caster, but only 1st level spells at first (only the leftmost column of spells known and spells per day is counted). Can be taken up to 9 times, each time granting access to higher level spells. Must meet all other requirements to cast said spells. Must stay divine or arcane unless one takes mystic theurge feat below.
e) Mystic Theurge. Prereq. Must be divine or arcane spellcaster. benefit: now count as both divine and arcane spellcaster, so can have familiar (with the right feat), can turn undead (with the right feat) and can wear armor and cast spells with no ASF%. This feat does not grant additional spells.
f) Improved BAB. BAB goes to Expert level. This feat may be taken twice, inc which case BAB goes to Warrior level. This feat may only be taken at first level.
Tadah! Now you have the truly generic class! One size really does fit all!