We all look in envy at what Crewe have achieved year after year yet we ignore their basic principle.
Crewe is a perfect example of how to bring youth through into the first team, yet they are required to sell these players to help fund the academy and also bring in players from outside the youths. They also had 5 loanees last season too.
So let's look at this system they use.
Nick Powell, now playing in the Premier league with Leicester on loan from Man U. In his 1st season in the Crewe first team, he managed 18 appearances clocking up a total of 260 minutes on the pitch - average of under 15 minutes per appearance. In the 2nd season he was a regular fixture in the side, 3,479 minutes played in 44 appearances - average of under 80 minutes per appearance.
Ashley Westwood, now playing in the Premier league with Aston Villa. In his 1st season in the Crewe first team, he managed 2 sub appearances accumulating a total 24 minutes. Only 2 more sub appearances in the first 7 games of the next season before being given a start which was followed by being an unused sub in the next game until he made his break through and finished the season with 38 appearances totalling 3,137 minutes on the pitch.
Max Clayton, out of contract at the moment but, due to his age, Crewe are out pricing him of a move with Bolton unwilling to pay that. Played a England u16, u17, u18 and u19 level. In his first 2 seasons at Crewe, he only managed 1 start with 29 appearances from the bench. The 3rd season was his break through, with 27 starts and 15 appearances from the bench. Last season was a disappointment with a Malleolar fracture forcing him to miss 28 games, but he still started 14 games with only 4 sub appearances. A total of 90 appearances over 4 seasons, with a total of 15 goals - 1 every 6 games.
What can we learn from this? The first 1 or 2 seasons should be helping the youth player embed them into the first team - using them as a sub for 10-20 minutes at the end of a game to settle them into the team with a couple of starts in cup matches. Then, if the player is ready for regular action, give them a few starts at the start of the next season to see how they do and how well they are settled into the team. So let's compare that to our players.
Compare those midfielders to our Jack Payne, who played 399 minutes last season over 15 appearances - average of 26.6 minutes per appearance. He has played more than Powell and Westwood combined in their 1st season. With 4 appearances so far this season clocking up 240 minutes - average of 60 minutes per appearance - with more first team starts looking likely, then we can expect to see him make up a similar amount of game time that Powell and Westwood had.
Another one to look for is Jack Bridge, doing very well in the development squad it seems and as the season progresses if he is still doing well it would be a good idea to give him a bit of a run out from the bench. Although, according to Coughlan he does play in the same position as Payne and we already have several good midfielders.
Looking at our youth strikers, Williams, Brown and Layne, this is arguably their first season. I know that Williams played last season, but 9 minutes over 2 sub appearances isn't enough "bedding in" for this season to be his break through season IMO. Therefore, this season would be their settling in season with some sub appearances from them between now and then end of the season and if they do well then maybe a few starts.
In conclusion, going back to something I didn't quote from your post, "throwing them in the deep end" is not the best way someone will learn. It doesn't happen anywhere in life, you don't give someone more than they can handle otherwise they will fail. Sometimes there are exceptions to this, but that is very rare. Even Cristiano Ronaldo and Messi were being eased into their teams as 18 year olds.
Also worth mentioning that Francis Laurent was banging them in for the reserves in his first season with the club and his first appearance, as a sub, came on 18th October - scoring a header. After 2 more sub appearances and a further goal - he was given a start against Leeds. This wasn't a "kid" either, this was a 22 year old with previous professional first team experience.