It would be cool if workers were able to become in their profession increasing the quality of the product or their durability or quantity. Imagine a shoemaker for the first time making his first pair of shoes. He does not know how to do that, he also does not have a teacher. So as a result his shoes have a poor quality.
At the same time after a years of working and doing the same job he could be more efficient and share his knowledge to others.
I think it would be amazing to have and it will increase the value of every character in the game, making them more special and unique.
In Australia we have this thing called TAFE, Technical And Further Education. It’s supposed to help develop a worker’s skills but our governments are cheapskates and prefer to poach skilled workers from overseas. In the game you could have someone in a profession attend a second level school during winter and improve their production by 5%, but you have to leave them in their profession, not use them for the military or as a general labourer. If you do they revert back to basic education level.