Originally Posted by JCoyote
...It should be possible to "promote" the unit upwards into something else, with a slight loss of exp. So for example your peasants with all the great experience could then get promoted into Billmen or Bill Militia, and lose a chevron or two. Basically, it's a group of soldiers that have proven themselves and are given better gear and some new training.
But there should be limits to what kind of units any unit can get retrained into. Things should follow lines, melee to melee, missile to missile, etc. The end result should be a less experienced but overall more effective unit.