Yes, problem is many of the really talented players are not in the best teams and get overlooked.
A talent scout should have the ability to see past the superstar team and look at the individual players, problem is most of them don't have this ability.
I have personally seen player/s in the lesser team/s who are doing 40 plus tackles a match and doing a phenomenal job in attack in a beaten side but get continually overlooked for rep honours - I just shake my head and go - there is another one they missed out on.
I half agree with you because in most sports I have played I have been that other guy. Good enough to really restrict the opposition superstar but never really given a go at higher level representation. But as I've matured I've come to the realisation why it is, or at least why it should be. 'Why it is' is generally because of what you said, players get reputations or look big and fast or whatever at really young ages and tend to just keep following it through.
I know when I step out for a game just exactly how I want to play, I know the rules and I try to play with intelligence, essentially I am a coach to myself during the game. Within minutes I know how I am going to limit their best player, how I will get around him and how I will stop him. But you can take 2 things from that. Firstly I am focusing on their best player/s, if their best player isn't that good, my performance may not be as good as it could otherwise have been. Secondly I can really only control my own actions, other players may like the way I play, others may not even take any notice of any effect I have. Superstars on the other hand aren't looking to limit themselves to being the best on ground, they want to be the best ever. As opposed to me taking a safe option, they might take a completely stupid option but drive themselves to pull it off. And then in doing so they make sure everyone takes notice, they can drive their team to be better, even if their actions creates some of their teammates to be slackers.
So if I'm a selector who has to choose one youngster, I'd pick the superstar every single time, because good coaching can make him better and the toiler is only going to be as good as he allows himself to be. A persistent toiler will make it all the way if they want to anyway.