This would really be appreciated by guilds with enough members to field more than 5 people in WvW, yet do not want to be a part of the inevitable blue dorito zerg that comes with the current commander tag.
If you cannot just make all guild members visible as gold dots by default the way nearby allies are green dots; please consider allowing a guild to set a number of officer ranks as unique icon tags that only show to guild members on the map, but in all other ways gives the same tools available to a commander.
(maybe have the guild buy the tags as a guild upgrade)