Mercenaries and Independent characters

A rough draft:

In addition to the regular members of a warband, each team may also employ the services of some external muscle, or their exploits may draw the attention of powerful individuals with agendas of their own, to help battling some particular foe. In game terms, these are called Mercenaries and Independent characters. Although at first glance there seems to be a little difference between the two, the mechanisms of how and why they fight are very different.

Mercenaries
Mercenaries fight for money, and little else. They can be hired with gold the warband has gathered, at a 'per battle' -fee. That means a beginning warband with no gold cannot employ one. Mercenaries can be used to 'round up' a warband, giving it abilities that it would not otherwise have, such as ranged attacks or magic. Mercenaries do not gain experience nor advance, and when cut down or ran off do not roll for injury but retire instead. Mercenaries do not count as the members of the warband regarding morale, although a mercenary receiving a Gruesome death will affect the warband it's fighting for normally. The fee for hiring a mercenary depends on the point value of the figure, and the value of the warband hiring, so that  a warband with lower rating will pay less to hire a mercenary, so they can be used to even the odds for an underdog. (Table? Formula?) Mercenaries generally do not care who they're fighting for, but some may have restrictions against certain species of factions. Mercenaries have a general title (although they can be given names, as well), and different warbands may simultaneously employ the services of a different Ogre Thug, for example.

Independent characters
Unlike mercenaries, Independent characters are named individuals, and only one of each may be at the game at any time. Also unlike mercenaries they cannot be just flat out hired, but rather may be fielded if the warband is fighting a foe that is also an enemy of the Independent character. Furthermore, the warband that wishes to gain an Independent character at their side should be an underdog in the coming battle, and the point value of the Independent should not be enough to tip the scales. Some Independent characters are faction-specific, and there should be at least one suitable Independent character available for each player. Like mercenaries, Independent characters do not gain experience. If they run away, they can be used in subsequent battles, bit killed Independents don't return in a specific campaign. They also do not care about the goals of the warband, and cannot be ordered to hold objectives and gather treasure and such. (Might have random objectives of their own?)