If possible, resources should cluster around one location rather than being found evenly throughout the map. This would instigate wars over resources, an idea which I really like. It would also require you to choose your city sites carefully if you want to go for higher-up Monopoly buildings (if my proposal is implemented, that is).
That is down to the function(Bonus Resource Distribution) I am using in AssignStartingPlots.lua, its unrestricted to layers/regions(Strategic/Luxury), to put it simply I used the function that caused me the least bit of trouble in debugging to get the resources on the maps. WHen it comes to Regions like you want it gets a whole lot more complicated and easier to mess it all up(still doable but 9/10 times alot of debugging rewriting code ect).
Edit:
Its probably easier to make our own Layer than go messing with the static regions/layers and set our restriction within said layer.