This never came to mind before, but has anyone ever thought about the option to convert axefighters to scout and swordfighters to knight AFTER they are already created? For example, if a player creates swordfighters at the "beginning" to have defense, but later decides that he/she needs some knights...and not enough iron and/or food is available, but horses finally are (whether it be from trading from the market or what have you), then...

For example, there could be a button next to the feeding button with a picture of a horse (for axefighters and swordfighters only, of course). If that button is clicked (and only could be clicked once), then if there are horses in the barracks or stables, the serfs bring them to the axefighters and/or swordfighters and then they become cavalry?

It would probably be stretching it to convert horsemen into infantry (because this would imply that weapons could be taken away from troops...which would then lead the player to wonder why you just can't convert any unit to another...which would be a mess), but I just wanted to mention this just in case (as always).