Dogs of War, like in TW:Med2 you could give a Lord a ability to buy mercenary units. Warhammer mercenarys where always called Dogs Of War. http://warhammerfantasy.wikia.com/wiki/Dogs_of_War
With this I got also a funny suggestion. You could make like random lets say heroes to join the army as a dog of war for 1 battle. For example you could add heroes like:
Empire:Gotrek & Felix, Luthor Huss, Mathias Thulman, Brunner.
Dwarfs: Malakai Makaisson, Gotrek & Felix, Snorri Nosebiter, White Dwarf
Orcs: Skarsnik, Golgfag Maneater, Skrag the Slaughterer,
VC: Arkhan The Black, Dieter Helsnitch, W'soran, Zacharias the Everliving.
Chaos: Crom the Conqueror, Wulfrik the Wanderer, Egrimm von Horstmann.
Make every one of em unique. With a cooldown, or with a request to join you in battle.
Bring back the Dogs of War to Warhammer World !
Sorry for my bad english ;(