I think the main reason why some teams seems to dominate some leagues is MONEY.

There are several reasons for my saying are few of them are:

Most of these teams that dominant these major league are those that pay their players high amount of salary. For example comparing the amount a Real Madrid players are taking to Real Bestis. One can see clearly that one player from Madrid salary can pay the whole players of Bestis. As a result of these all players who develop from Bestis will want to move to Madrid in other to male a leaving.

The second reason is the money these dominating teams use to buy new players. For example, Aston Villa and Man United trying to get the same player from Sunderland. One can conclude easily that Man United will end up getting the signature of the player before Villa because United might offer huge amount of money the cant be payed by Villa. A lot more reason and examples can be given.

I think one thing can be done to stop this, which is restricting all teams to spend the same amount of money and those who are not having, the FA will find ways of providing it to them to pay later. I guess in this case those teams with huge amount of money cant pursued those small team player them with money to play for them.