HYPER DOOM PIXIE
I did notice something though. One, that the distribution of skilled vs. less skilled seems a bit skewed, and two, that the healers and engineer-style mages should probably be in different proportions at different levels, as well as having other abilities at the higher levels(a second-circle earth mage is great at fortifications. And at pretty much anything else, too. Like making earth elementals. Or causing the ground to eat people.). Just saying; not as simple as 'X percentage know Y magic', at least if you want realism(to the degree that it's magic and there's realism).
For example, I would think it might be more like 4 Second-Circle, 26 Third-Circles, 180~ Fourth Circle, 60~ Fifth Circle, and 40~ Sixth Circle.
Second Circle: 1 life magic specialist, 1 earth magic specialist, one thaumaturge, and one illusionist(Second-circle illusionist. Sounds dumb, but when you get that good...dear lord...)
Third Circle: 7 life-magic specialists, 3 earth/metal magic specialists, 2 water magic specialists, a wind/weather specialist, a fire specialist, a necromancer, Muse, summoner/planes magic specialist, Hyper Doom Pixie, 'psychic', Forge-magic specialist, Teleportation expert, Divinist, 2 Ward specialists, Blaster
Fourth Circle: 32 Healers, 8 Disease-specialists, 7 Life-magic specialists, 6 Light-magic specialists, 8 necromancers, 6 summoners, 9 illusionists, 2 shadow-magic specialists, 22 earth-magic specialists, 8 'crafters', 5 Diviners, 8 enchanters, 5 Muses, 3 Animal-magic specialists, 26 teleportation experts, 4 Water magic specialists, 3 Wind Magic specialists, 1 fire magic specialist, 2 'psychics', 7 Ward specialists, 1 diplomancer, 9 Ritual specialists(all work together, usually)
Fifth circle: 20~ Healers, 4 Ward specialists, 2 enchanters, 1 diviner, 3 forge-magic specialists, 5 teleportation experts, 3 shadow-magic experts, other. Varies from time to time, as these aren't the professional mages the above circles are; they're people with a good amount of magic talent that also happen to be in the army. Probably soldiers a good deal of the time, and go attached with squads as necessary for support on a small-scale basis, rather than the support and specialized duties the others fill.
Sixth Circle: Varies greatly. I view these as little more than the camp followers with magic.