What do you think of a 'tag' option for names? On a players settings page there would be a field to add your clans tag before your name that way you wouldn't have to bother with name change requests and people can update this field if they leave, change or join merc units.
For example if I was a lone wolf I would simply be Fiachdubh but if joined Spectre's Ravens could add a SR before it for 'SR Fiachdubh' or if joined Clan Ghost Bear could change it to 'CGB Fiachdubh'.
To avoid having to check every tag for rudeness each Merc unit would select their tag alongside the unit name when creating their unit in game (or however it will work) so people can only input registerd unit tags.
I believe this is already a planned feature.