Is it for achievement or your longer plan not to buy any players in?
For achievement it's easier to choose some early cup match, same thing as very young line-up winning a match.
I haven't seen any 100% homegrown and very successful team in competitive leagues. For success teams need some more super-players, mostly supertalents or players from better base than you have. Having all players in very short age range will mean that team might have sharp period couple of seasons, but then will fall quite quickly too. I prefer team with more sprayed age range, so it can run smoother, without big ups and downs. Your team has already quite good facilities, so you may try it. You also need good ST rising just to one of core players....or you are ready to go down for some period. Most of bigger leagues have some "project teams" who collect nice young squad and go maybe down couple of league levels, then start to rise and when hiatus is over, sell them and start with new wave.
Academies don't produce big number of youngsters per season and there is some weaker pulls too, who maybe don't reach to needed level.
My second team will be probably such kind of club next season after relegation, but it's consequence of money collecting plan. I'll sell my bought-in players, some older might become to staff and my Austrian-Kosovan squad will not be promotion candidate for some seasons. My first team is also mostly homegrown team with just 3 players bought in and is quite out of first half play because my midfield remained too weak after aging of my ST and next season might be more in relegation fight. For both teams it has been money collecting period and when building phase is over I'll probably buy again some players in.