Hard and fast 'limits' strike me as lazy. We should assess something based on its individual merits, whether it's age to start/end being a pastor, qualifications for a position, age to get married or become a parent.
Sometimes we need rules for society. Child labor laws for instance (even thought that has been problematic for family farming) because without such rules, people are abused. But whenever possible we should assess each person, situation, proposal on its own merits. I think there are many young people who've had enough life experience and learning to be excellent pastors. And there are people who've been alive for 50 years who still have not experienced enough in their lives to have empathy for others (a critical gift for pastors!). I guess that means I vote No.