I personally think that the stamina usage on iron tools and steel tools are bit too high.
summers growing up I had a job swinging a sledge hammer and pick axe to level off land did that for 3 years.
iron is more than twice stone tools stamina usage, and steel, which isnt really harder to use than iron is more than 3 times the usage. 8, 19, 27 for stone, iron, steel. i could understand a 50% increase in stamina usage, but more than double?
i am testing out 8, 16, 24. and it seems to be smoother. havent really gotten to steel yet on my playthrough