I think where the problem comes in is in the application. I have seen in the Lutheran church where "calls" will be sent to pastors who already hae a congregation they are serving. I am told that then they have two calls and have to decide whether to take the new one or stay with the old one. This can be rather disruptive to a church. My daughter's pastor was young and he would get a new call about every 4 months, and eventually left after a couple years, but it always was stressful for her because she had built up a working relationship with him as a spiritual counselor and when you lose that, the next pastor may or may not be a good fit, besides all the learning curve that the new pastor needs to have to come up to speed on the sheep. It seems as though pastors abandon their sheep, and effectively they are left shepherd-less for a while, sometimes a year or more, while they are trying to find a pastor.
I like much better what I see at Anabaptist churches where they will have several ministers, all pretty much selected from among their congregation. The church we have been attending had 4 ministers. One retired and it took about a year to replace him, but now they are back to 4. These ministers are part time so are not paid, though if they have a need, the congregation would help them. They basically surveyed the congregation for suggestions on who would make a good minister, tallied the results. There were two candidates that got a lot of votes but it was too close, so they figured that it was not the right time and put is aside for about a year. Then they did it again, and it came out much stronger for one man and he was selected. Of course, one of the ministers is the head minister for purposes of order.