Grumble, grumble...
Now that I finally have gotten my sourcebooks in the same location (I.e. the "Magical Medieavl Society" and my DMG), it seems like there may be some errors in MMS's demography tables. I asked for more info on Expeditious Retreat's bullitin boards, but meanwhile here's what I came up with using the DMG's demographics rule on pages 139-140
The highest level NPC of any give class is given by dX + community modifier, where the community modifier for "Small City" is equal to "+6 (roll twice)".
For example, for Rogues, the highest level NPC would be given by "1d8 +6 (roll twice)". In other words, there are two Rogues of levels Rog7-14. For example, one Rog9 and one Rog12.
The number of lower-level NPC's of that class is given by the following rule: "if the highest-level character is 2nd level or above, assume that for each such character there are two of half that level." For example, for our Rog12 there would be two Rog6, four Rog3, and so on. If you get into fractional levels things get a little ambiguous, but the example in the DMG seems to indicate that you round up at .5, and keep using the fractions for the next levels. In total, starting with the Rog9 and Rog12 as highest-level Rogues, we get:
1 x Rog 12
1 x Rog9
2 x Rog6
2 x Rog5 (4.5 rounded up)
4 x Rog3
4 x Rog2 (2.25 rounded down) + 8 x Rog2 (1.5 rounded up)
8 x Rog1 (1.125 rounded down) + 16 Rog1 (.75 rounded up)
Here are the numbers for the other classes (I picked some reasonable values for the die rolls, e.g. 2 and 5 on "1d6 roll twice"):
Paladin, Ranger (1d3+6, roll twice):
1x9, 1x7, 2x5, 2x4, 8x2, 16x1
Aristocrat, Barbarian, Monk, Sorceror, Wizard (1d4+6, twice):
1x9, 1x8, 2x5, 2x4, 8x2, 16x1
Bard, Cleric, Druid, Adept (1d6+6, twice):
1x11, 1x8, 2x6, 2x4, 4x3, 4x2, 16x1
Fighter, Rogue, Warrior (1d8+6 or 2d4+6, twice):
1x12, 1x9, 2x6, 2x5, 4x3, 12x2, 24x1
Expert (3d4+6, twice):
1x15, 1x12, 2x8, 2x6, 4x4, 4x3, 16x2, 32x1
Commoner (4d4+6, twice):
1x18, 1x14, 2x9, 2x7, 4x5, 4x4, 16x2, 32x1
(The rest of the population is filled up with 91% Com1, 5% War1, 3% Exp1, 0.5% Ari1 and 0.5% Adp1.)
The highest level you can roll for any PC class is 14 (on 1d8+6), so I would suggest we make Lady Kelvin a 14th level NPC.
These numbers also give us guidelines for the "Government" thread. For example, the head of the Mages Guild will be a 9th level Wizard or Sorceror, and the city only has a total of 30 Wizards and 30 Sorcerors (and most of those are lvl 1!) On the other hand, the head of the Thieves Guild is likely to be a 12th level Rogue, and there are a total of 48 Rogues in the city.
With respect to the NPC thread, we probably want to restrict "free for all" submission to a certain level, and have an actual contest for the highest-level ones (probably in cooperation with the Goverment thread). I think lvl 5 max is a reasonable limit for the NPC thread.
[Edit: cross-posted to NPC and goverment thread]