Personally, I set them to the individual roles.
Youth players I work on individual stats that need increasing until I'm happy with them, then once they are about 18 or so, I'll set training to the specific role. Others may do it differently though.
Youth players I work on individual stats that need increasing until I'm happy with them, then once they are about 18 or so, I'll set training to the specific role. Others may do it differently though.