Sounds like a lot of people in this thread didn't attend a class on economic history. There's plenty of evidence for advanced financial techniques even during the early Medieval period -- after all, Genoa really got going as a financial center in the 12th century, and the Mediccis and Fuggers got their start not long after. Now, before you're all "but dat was local or some such I am ignorant wah", these folks were using letters of credit and double entry book keeping -- modern practices -- as
Aeon221
Ah, see, swwu, you misunderstand me. I'm talking about the commander of the unit, not the unit itself. The unit could be promoted in whatever way is implemented. Although I would definitely argue that there are plenty of marine platoons out there that have earned the drunkard trait.
Just to answer a few points, I did not intend to suggest that the developers write the story for each of these units. That's dull in the extreme, and generally ignored by most folks. X-Com's style of generating units is a little closer to what I mean than, say, the prewritten histories of heroes in Romance of the Three Kingdoms (by Konami). I also want to emphasize the importance of traits as seen in the Total War games, where an idle unit might pick up the drunkard trait, and a unit
If you take a peek at any military text from the Medieval or Early Modern eras, there's a strong connection between the commander of a unit and his troops. Sometimes it was hereditary, like an enfeoffed gentleman leading a company of dependants from his lands. Equally common was the practice of raising troops via captains. Unlike the classical practice of raising a unit and then appointing a commander, Medieval and Early Modern governments tended to appoint a commander, pay him, and give him