In my OG post, this youth team would be optional. Just like having a development academy youth team is optional for pro teams to have.
Real World Example:
A team in major league soccer doesn't HAVE to have a youth team since the MLS has a draft like the NBA. They can however if they Chose to like the Philadelphia Union for example. The Philadelphia Union have a youth side where they develop and compete with U17 aged players. Some of those players can be signed to the major team if they decide to bring them up. All the while the MLS Still has their draft where they select players coming out of college. Hence the ability of having both the BB draft and also a BB Youth team.
The Skill Sets:
The drafted players would be the ones whose skill set you will already know as we already do now. That would not change at all. The youth team players would be randomized with their full skill set only being fully revealed after being on your team for a full season.
Where they come from:
These 15 to 17 aged players would be randomly generated to fill out a full initial youth team if you Opt in to having a youth team. Then, Similar to hattrick but a little different, your scout would periodically have new youth players you could bring into your youth team up to a roster of a max say 12 players. Your Youth Scout would find 15 to 16 yr old players but never 17. At the end of the season, you can then sign 4 or however many of the scouted 15 and 16 yr olds to your youth team which would allow you to maintain the 12 man roster despite players aging out of it.
End-Of-Bench to All-Time-Great:
The actual potential of the youth players would be hidden, and you would just have to monitor their growth to gage it. Their Potential would be the only element of them that would remain hidden until you sign them to your major team. These are youth players, kind of hard to honestly tell if someone could be an all-time great before their even 18. They have Potential ratings from jump street, you just won't know what it is until you sign them at 18 if you bring them up.
Lastly:
Seventeen is simply the max age a player can still be while on the youth team. At 18, you either promote them, or cut them. If they are cut BUT have a minimal TSP that would actually make them a decently usable player at 18 like say 50 TSP, that cut player goes to the FA market. If they are a terrible player, they just disappear upon being cut.
The initial team of players generated for your team would consist of an even number of four 15yr, four 16yr, and four 17 yr old players for your 12 man roster.
Hopefully this additional info covers some of the questions and comments made so far. Im glad the discussion here is starting to pick up a bit.