I thought courts martial and secretaries general (and Knights Templar/Hospitaller, et al) were Anglo-Norman/French borrowings. Do you have any examples of native English phrases following that pattern?
A relative presided over a couple of court martials (1) in the past. Modern usage has largely disconnected it from the past, grammatically (if that is even a thing, except to the true minutaephile)!
(1) https://www.gov.uk/government/publications/court-martial-res...