But my youth player will still be a fast trainer next season and the season after that. Your scout player will slow down in speed while my player will regain his stars for the next 2 seasons with minimal power training. Usually my scouts last 3-4 seasons and 5 at max. I had a youth player since level 1 and I still play him in my first team, currently 6* and he'll still be in my team for the next 2 seasons. So unless you have a team full of 22 year old scouts, covering every position, quality ending in 4 or 9 and are decent trainers then there's no harm in investing in a youth player as well.
it didn't even cost that much actually. It's a 1 to 1 ratio until 6* and then a bit less from there.. So probably 150 tokens which will make that player last at my club for 5-7 seasons