Giving the freedom to post any number of posts per week is good, but hiring someone who will only write 5-10 quality posts per week will only benefit the forum and not the client side - the client is looking for numbers (to have their signature display many times per week)
But if manager is not satisfied with the amount of posts someone is writing on the weekly basis, why even hire him in the first place? Or if someone changes posting habit in a way that no longer fit the campaign, manager can always replace him.
the client is looking for numbers (to have their signature display many times per week)
The manager should be able to explain to the client that there are other factors at play besides sheer numbers (ss we know, there are managers who can do this and their campaigns have no minimum).