Accounts Servant is usually a Ministerial Servant. Sometimes an Elder. Very unlikely to be a non-appointed man unless there is a real shortage of brothers.
I know of one hall where the Territory Servant (maps) had a non-appointed man (ex elder actually) but only due to having not enough servants.
Here is how it works.
Accounts nearly always has a servant if there is one available. Sometimes an elder.
Mags dept and Lit dept might be combined under one servant (if there is a shortage) and each dept has a non-appointed assistant.
Maps usually a servant. Rarely a non-appointed man.
Sound - most likely not to b a servant if short on bods.