Mark
You are welcome.
From memory, in the FIW up to the 1750s, all regular officers were senior to Militia and Provincials. This was changed to senior to same grade regardless of date of commission. Same for the AWI. However to ensure that regular officers held command, higher local rank was often granted to regular officers.
I seem to recall that regular officers commanded all (most?) brigades of Regulars, Fencibles and Militia etc. in Ireland.
See Sir George Prevost to Major General Isaac Brock in 1811.
Page 135.
https://books.google.ca/books?id=DgJmAAAAcAAJ&pg=PA135&dq=
Good hunting.
Ron