Add function to re-school/re-educate units

Anyway, we all know the problem with buildings which use finite resources; fish, coal, iron ore, gold ore. Once you deplete all resources you can get your hands on, you can destroy the buildings and place other things there, but the miners/fishermen will just sit there, be AFK, and eat your food.
So that got me thinking. A 'kill' option is not KaM-style, I read somewhere. But what about a re-edudate function? It could cost like 2 or 3 gold chest (sorry, don't know the English names, I always play in my own langauge

I think it would be great idea. It's not as barbaric as just killing your villagers, but you could re-educate them to something else. Hence, maybe even limit the re-educate functions to Serf or laborer only! At least it's not such a waste as it is now. As it is now, the only way to prevent useless workless people is to not build those buildings in the first place, meaning that at the very least you have to buy coal and gold ore from the Market.
Any thoughts?