I can't think of an RTW EDU function that would act like having a 'shaman' attached.... things can come with an officer but unit stat's abilities apply to the whole unit. If you give things druid / warcry attribute the whole lot is effected by the animations / sounds

The 'command' function that's used for the Eagle bearing units in roman factions is one possibility to adapt as that has a morale factor attached, so you could have your new building recruit the 'eagle' equipped version of the unit (old one wouldn't upgrade to it though)


Using them to give traits /ancillaries to generals stationed would be the more conventional approach.