Are the garrison requirements of an urban settlement in the borderlands 3gp per family per month because the settlement is located in a borderlands hex or is the minimum garrison 2 gp per family per month because it's an urban settlement and urban settlements always have 2 gp garrison minimums?
At first I thought that urban settlements in borderlands and wilderness areas would be more lawless and require beefier garrisons to keep the peace and discourage bandit raids but on a reread I think maybe this is not so because the urban expenses table doesn't give garrison costs as variable.
Since an urban settlement is a dense collection of people, it makes sense that the garrison costs would be lower. There's less area for the troops to secure. Additionally, while the per family cost is lower, since there are more people in a small area, the total securing force will be bigger/more elite. A similar phenomenon happens when the non-urban hexes go from wildernss to borderlands and borderlands to civilized. This is all to say you should assume that the urban settlement garrison is simply 2gp and doesn't change depending on where you build it.
That's a relief. The economics of rural urban settlements looks a great deal more reasonable from that point of view.
Just as Jard said, it's always 2gp per family.