I'm going to use a 60-year period, divided into three 20-year ears, to do the initial population. Since this is a wilderness, I've created three separate race probability tables reflecting these eras, with the earliest tables weighed to favor the typically evil races, gnolls, goblins, and the like. For each year, I'll roll a die (probably 1d6-1) and generate that many new groups for the year. I'll also use a die roll to see if the new group is native or a new arrival, with the odds of native groups dropping each era.
With average die results, this will give me 210 groups, about three per 36-mile hex. That's too dense, but I'll take care of that along the way. Once they're on the map, groups can discover the terrain features near them, which is kind of the point, but they'll also have to deal with seasonal events each year, hostilities, disease, poor harvests, demon attacks, a crisis of leadership, and more. Events can strengthen, weaken, or destroy the group, and might produce terrain features along the way.
I've tentatively assigned some base attributes to groups, Size (total members), Leader (strength of leadership), Might (military power), and Resource (wealth, goods and ability to gain more). I'm going to keep this simple, 1d6 plus bonus based on group type and race. The final results look something like this.
That's pulled from Excel, showing one complete entry for each of the three eras. Obviously I won't use all these at once, but now I can generate new entries at the push of a button.
Of course I'll also need to place groups as they're generated, and I'm still pondering how that's going to work. I'll probably decide based on arrival vs. native, race, and randomness. For example a group of Native Lizard Man Nomads is a wandering tribe, so I'll randomly pick a wetlands area for their starting position.
So let's see how this all works shall we? The die roll says Y01 produces: five groups. Stealing a page from Traveller I'll be noting these as: Race Type SLMR. Here they are:
- Lizard Men Pilgrims 4856 (Arrival Summer)
- Lizard Men Military 4475 (Arrival Winter)
- Goblin Pilgrims 8457 (Native Summer)
- Gnoll Military 7991 (Arrival Autumn)
- Goblin Pirates 4784 (Arrival Autumn)
Edit: Added info on whether or not the group was a new arrival or native to the area. For new arrivals I also added the season of their arrival. For native groups this represents their first significant appearance.