Of you have a modern collection I think it can easily be 15-20 pcs.
Have 4 sterns myself, almost never an issue
Friend has 8 sterns, same experience
Another friend has mix of 9 pcs stern and BW, think we have 1 technician evening as I call it a year.
So in a home use environment I see little issues. If you have older pins I think you should give them a good service and shopping job after purchasing and should be fine to.