What perfect Church is it that you belong to that has no clergy that sins?
There are no perfect churches or denominations. That’s the point. If one claims “one true church” that implies the “true” part means they do all things justly and right. Plus we are not just talking about teachers but men who took vows, hear confessions, oversee and perform holy sacraments. Much more is expected and required of these men.
So no church is perfect, but you can measure the effectiveness of their claims by how they follow their own rules and authority.