If you read the article regarding Breel Embolo [
http://foot.ie/threads/147164-Eligib...=1#post1805274], you will see that the Football association of Cameroon did not submit all the relevant documents at first and that it had the effect to delay the process. In order to avoid such stalling tactics, I am assuming that FIFA sets a deadline to comply and clearly indicates that it can decide based on the record as it stands.
The judge has to appreciate all the documents, especially if an exemption from Article 7 is requested. To date, only one request to change affiliation has been denied. All the other requests - not complying with the relevant regulations - have been withdrawn before they were submitted to the Judge. This is why there is a pretty high success rate.
Of course, the case of Breel Embolo concerned the granting by the Players' Status Committee of an exemption from an application of the article 7 criteria rather than a request for change of association, but the judgment process is similar in practice. The reason why the football association of Cameroon had to be involved was so that they could confirm that Embolo had no international cap with them.