22/23 year old scouts that have Q's ending in 3,4,8 or 9 beats 5* 18 year olds, unless your planning on training players to at least 8* each season.

Cost to train an 18 year old an extra role+SA then bring to 7* is around 200 green boosters. If you can get optimum scouts on your list its better to take those than develop many young players.