I thought I was getting more wool from the stable after I upgraded and one of my mines seems to give better drops and they are 1 level different. I do not keep track of my drops though, so not sure if that's accurate. I bought sheep also, so it just may be my perception of not needing it as much as I used to. This game seems to go from maxed out to extreme shortages. part of the reason I love to play is trying to figure out what I'm going to need a ton of next.