Simple suggestion but I think that whatever wolf you have assigned to Fishing or Mining should gain a small amount of EXP for each successful activity.
It could be based on the level of the activity itself:
- 5 exp for fishing in peacful pond, but 10 exp for backwoods brook, 15 for frozen fjord, etc
- 5 exp for sucessfully smelting a copper bar, 10 for an iron bar, 15 for silver etc.
This could be a nice way to level up wolves that you may not take exploring or send on hunts.