I would think entirely that way too, Ardith, however
helpfile wrote:
Well trained leaders are essential on the battlefield and there is no
better trained in the arts of war than a mercenary. Through tactical
directionsand sheer personal magnetism, a mercenary has the ability
to exert his warband to greater efforts by performing a rallying cry.
It's that little part, along with the whole frenzied/berserked people not working thing that makes me feel like it's more than just a "SONS OF ROHAN GRAAAAH!"
Although I guess the argument is kind of moot. No matter what the skill implies, the answer by D = balance.