Not the same at all. Olajuwon went through the same naturalization process as anyone else who earns US citizenship. He's an American in the same that everyone else who waited and got US citizenship (which according to our constitution is equal to a natural born citizen with the exception of the ability to run for president) Anthony Randolph required an act of the Slovenian parliament to grant him immediate citizenship so he could play in a European basketball tournament. Governments granting citizenship for the purpose of tournament play is very different than following the normal naturalization process.
It's my understanding Randolph did what many do across Europe, FIBA allowing one per team or something like that. It's not just Slovenia.