3 heavy sets of farmers can be pretty taxing on your grip. Keep farmers at most once a week and grip once a week. If you know you have a heavy farmers day coming up, cut back your grip workout.
Heavy farmers never affected my crush or pinch grip training but the inverse is not always true.
Increasing your grip volume is a double edged sword. You need to do more to get stronger but if you do too much, you'll get weaker and your hands will hurt all the time.