Is it too quick and easy to make leather? It's possible to bring down a stag or elk with a single primitive spear and it takes a few seconds to gut it so the step of obtaining raw materials (pelt) is about the same as say, mining a surface ore. Converting those ores to bars takes quite a time and an additional fuel resource although it doesn't stop the player doing other things. For leather, slapping the pelt on a tanning rack and giving it a few seconds of scraping creates the final product. I haven't timed it but I feel that creating yarn takes longer which doesn't seem right.
A slightly more realistic process would be to place the leather on the rack then require some resource to be added (eg tannin) as a second step but that requires additional systems, graphics etc. Personally I think the present simple system is ok it's just too quick... maybe the production should increase by 5% or 10% steps instead of 25%...?
