I cant see local distributors or local players being happy with English cards being used from sets that have yet to be be released in the local language.
If a distributor is going to all the trouble of getting the cards translated and the associated delay they will hardly be happy with having their market destroyed by the import of English cards from America.
If a large number of locally unreleased cards are allowed at League then all that does in encourage League players to import. This is not exactly the desired outcome that a distributor wishes to achieve by supporting League.
The only resolution to this is to ensure that the delay between release of the English cards and the local language cards is kept to a minimum. Certainly the local cards should never be allowed to get several sets behind.