Freelancer is awesome enough that it's been embedded in a growing number of the larger mods, like Brytenwalda and Floris.
Freelancing can be a double-edged sword though. It lets you level up and gain good equipment (and keep it under certain conditions), but it also means that when you leave the army you'll be a high-level character without a warband in a world that scales its difficulty against your level, plus the diplomatic map might have changed significantly.
I served in my dear friend Count Trimbau's army for the period of one year (20 hours
), and left at ~level 20. While I had noticed roving groups of hardy mountains bandits in the 20s-40s, they didn't cause me much trouble; I used my savings to purchase the service of a few intrepid mercenaries, and went about gathering a few recruits. Frankly, I could probably handle at least a dozen single-handedly on average difficulty without a horse of my own. Bandits are generally puny and go down easily once you have a ranged skill at 150+. One of the huge advantages to Freelancer is that you wind wind up with disproportionately high weapon skills from the constant hack-n-slash, with none of the time consuming drawbacks that come with maintaining or losing your own men (recruiting, scratching together money through long and tedious quests, etc.).
As for the local lords- I've found that that the majority of them have 30-80 some men per band, the exception being Kings and Marshals with their ~150 men warbands. From what I can tell, numbers have mostly stayed the same as they were when the game... if anything, I'd say they've decreased for some lords, on account of the constant fighting. Currently, I'm marching about with my army of 70 men, and find that we can usually topple any group no more than 100 strong, and quality over quantity seems to be a good rule of thumb- my sharpshooters, sergeants, and knights make quick work of footman, light cavalry, and skirmishers that are the staple of most armies.
The one things I have noticed and loathe, is the rate and number of times with which lords defect, which is, in my opinion, absurd on so many grounds, game-breaking, and not to mention annoying to encounter when you've stuck with a single faction the entire game only to to find yourself competing for fiefs with some random fat-head from an irreconcilably "barbaric" culture who will probably defect again at the end of the month. At least in Romance of the Three Kingdoms, which suffered from this like the plague, you had to option of executing turn-coats.