The resources do need some work. Here is the current distribution of resources in TLR 1.9 beta 5, by number of uses.
timber 72
iron 50
furs 42
silk 29
wine 26
dyes 24
cotton 22
slaves 21
sugar 21
wool 21
silver 19
sulfur 16
amber 10
coal 10
fish 10
gold 8
grain 8
marble 7
tin 6
textiles 5
tobacco 4
ivory 3
chocolate 2
Total 436
Clearly it needs some work. Does anyone actually put a merchant on timber? It can be cut down. Furs too. Iron is probably a bit overdone. And silk.
And spices are missing. Salt was one of the most valuable resources in medieval Europe, often being worth more than gold. Frederick Barbarossa's family grew rich and powerful in Swabia because of its control over most of the salt mines. The search for better trade routes to the eastern spices in general instigated the great Portuguese and Spanish naval explorations of the 15th century and sent Marco Polo east as well.
There are a total possible of just 199 provinces, yes? Even if every one was a town and had a grain exchange, that's still only 199 possible merchants on the map in the most extreme circumstance. To me, then, 436 resources seems a bit much. Maybe a compromise in between somewhere.
Right now, I'm researching medieval sources for the main exporting regions for each. I'm finding all manner of useful information, such as dyes - especially Polish cochineal, an insect which produces a vivid red dye - which were the leading export of Poland and Lithuania in the 15th century. Or that sugar cane was introduced early by the Moors into Spain and was produced near Lisbon and Seville. Scandinavia was a leading exporter of sea ivory - ivory from large sea mammals like walrus and whalebone traded to them from the Finns further north, and the Hanseatic League trade in that type of ivory directly competed the Italian monopoly on African and Indian ivory trade leading to much contention between the two great merchant powers.
Fun stuff. Typically, I'll end up losing myself in all this and come out the other side in a few days with an utterly useless knowledge of something only marginally related but which was highly engrossing. Heh.