Measuring academy success of the rich (and elite) clubs is often reduced to a question of how many players make it into the first team of the parent club, but this type of analysis is superficial.
Manchester United and Arsenal are often held up as some great and noble success promoting youth, but when you look a little closer they may be considered as no better or worse than the the 'rich' clubs as defined. Utd's approach was a brute force industrial process starting decades ago, they built an exceptional scouting network and took all the best UK talent they could find from an early age and ended up with a handful of exceptional players. No doubt they have an excellent academy system, but it's difficult to say it's totally superior to other clubs when you consider the scale and cherry picking of available talent. Arsenal did much the same, but with a wider scouting network extended into Europe. All the big clubs look to copy this model, only now the scouting networks are like some kind of nuclear arms race and the the clubs are vying for the best talent in Africa, Asia and the Americas as well.
You'd really need to find a detailed breakdown of the number of youth players entering each academy compared to the number leaving the academy as successful players in each division and league they end up in, as well as the ones that don't get a career in football. I strongly suspect that in any given year the best academies are not the ones at the biggest clubs, but those at some smaller well run clubs that are more efficient out of necessity.
Since Chelsea are the poster child for 'rich' clubs: the club has invested vast amounts in youth development in the last few years as they attempt to catch up and ultimately out gun their rivals, the results are actually an unprecedented number of players out on loan to 1st and 2nd division clubs across Europe. Is it a failure because few of those players will be in the Chelsea first team squad? Perhaps it's a great success, but probably the success rate is appropriately proportional to the money invested and the number of youth that entered the system.
'Big' clubs and money have always dominated, Fergie's Class of '92 was something special and it's unlikely to happen again. Compare to now: how many of Arsenal's and Utd's youth academy players coming through in the last 1-2 years would make it into the Chelsea first team squad? probably Jack Wilshere, but any others? I'm struggling, Utd have great players but no academy name is standing out.
For me, none of the mentioned clubs are particularly clever, insightful or morally superior, they're not doing a noble service to football or doing things the 'proper' way. It's just less conspicuous to spend vast sums on the youth system than headline transfers.
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