How does this sound to you...
There are a number of "champion mercenaries" (which I'm calling so now, for lack of any better term at the moment), which function as hero characters and will most likely persist through the entire game, in full view of the player. Maybe even whomping on Dranton in a tournament or two (by the way, I am totally fixing tournaments so you get a melee weapon if you're ranged - arrows as the only weapon is shyte). These mercs will each be unique, and will work for any lord, occasionally offering their services to the player. They are high-level troops whose equipment cannot be modified like normal heroes, though they can be leveled up as normal. In order for a player to hire one of these troops, he must be captured and spoken to, or met in a town, then be paid an amount of cash (which will be a lot) for a starting bonus after being persuaded by the player. Whether or not he or she joins will be a factor of the player's persuasive ability, past relations, and how much the player's willing to shell out. These freelancers will leave the player's party, however, at the slightest inclination, or until some contract expires, then go seek work with other lords. How does that sound for an idea?
And concerning your Warlord concept, Weim18, I'm starting to like the idea. Might actually be fun to program, if I have the time. This would be something that happens every year or two of gametime - suddenly Beowurg the Bombastic (or whatever - that was the name of an old Nord test character of mine) from the native Nord country shows up with his army to attempt another takeover. He'll continue to fight until defeated. During this time, however, the player can decide to join up with him, working with him as if he were a normal king. That might be doable, presuming I can sufficiently test the mod to work out all the kinks.