Everyone has seen and/or created their perfect 'Class Creator' for their game system. They take into account most aspects of the classes and assign point values to each ability in order to custom build classes players may want to play.
This isn't one of those things, lol. I took the monster XPV chart and the adjustments used for monster abilities and built the class XP values for each level through 10th. This is all highly a mental exercise for fun, but if you consider that a HD is a HD no matter the values and spellcasting and combat ability balance out, here is how I assigned the adjustments:
Cleric - Starts out on the Class B Level monster line (equivelent to 1-1 HD), +1 for turning ability, +1 for 1st/2nd level spells, +1 for 3rd/4th level spells, +1 for 5th level spells.
Fighting-man - Starts out on the 1 HD line, +1 for combat ability.
Magic-user - Starts out on the Class A Level monster line (equivelent to 1/2 HD), +1 for 1st/2nd level spells, +1 for 3rd/4th level spells, +1 for 5th level spells.
Keep in mind I'm using the Onn XPV chart (adapted from Swords & Wizardry Core Rules), but the XP chart looks like this:
|If Characters needed the XP they are worth as Monsters to Advance|