I think we kind of have done that though! Donnelly fits that category perfectly from what you said Chicago and he's Irish to boot! Egan from Sunderland was a good example but too many don't even make it at football league level, how they were in PL academies I don't know. Jet came from Arsenal but found clubs higher than us. Osadebe came from Spurs somewhere down the line at least, Garmston from West Brom.
Donnelly was quite highly rated and was on the fringes of first team at Swansea but he came to us to get first team football. He has hardly set the world alight and I think there is the problem. These players have to be released at the time we need them, be close enough to not be picked off by smaller (but still bigger than us) London clubs and play in a position we need. We can't take extras just in case they are any good because we won't have the salary available, if we have a slot for a striker we need that player to be able to score goals. Chances are unless you know them well, taking a punt is better off used on one of your own academy players instead otherwise there is no point having it.
I do agree with you but there are too many variables. In my eyes there are a few gems if you are lucky to find one but most end up out of the game for a very good reason. Trouble is too many sit at huge clubs dreaming of being the next big star and think they are God's gift. They assume they will become stars and kids at that age want to have fun and not work hard and this will get worse the bigger the Premier League gets. They then get released and it's too late to prove their worth unless they are able to get a Conference side club and attempt to work their way up again like Adam Birchall tried.
