They had their own strategies and it would be foolish to think that they didn't have thier own desires and knowledge. They were choosing the European powers which they thought would serve their cause, that is why some supported one European power and the others supported another European power. Their role was great because they knew the ground well.
The quota system limited the amont of foreigners/immagrants allowed in the US from each different foreign country.
Th group affected most by this were the Europeons.