Havent had any issues getting 50+75 cones in a season to train SA and increase a star at least. In a season you can probably do 2 stars and an SA/New Position if you train moderately. What you can do is collect 130 cones then decide what you want to do. If you decide on SA, make sure he is already competent in playing that role. If not an SA will not help him be better. eg. if he is already good in taking freekicks then train him fk SA. It will increase his conversion rate.