I have a mod whose information may be found in the links of my signatures.
I have added offices like Archistrategos, Dioketes for Hellenic factions, Eran Spahbed, Ewenbed, Hazarbed, for Parthians, and Legatus Legionis (legion commanders) for Romans and local governors, roman governors, hellenic satraps, hegemons, etc.
During the searching I think that to use your legion banners for my ancillaries that I added offices as ancillaries would be awesome.

Note: I am not developing any new mod I just made a submod that may be adapted to any RTW mods currently I adapted my submod for EB.

What must I do to take permission from your dev team or from whom?

Thanks beforehand
Atra