So? We have thousands of registered S2 users, even if just a small fraction uses a racing number there's bound to be duplicates. Anyone can use whatever number they want, noone has exclusive rights to one.
Are you occupying racign numbers all over LFS? That's nonsence. It would be the same as taking a numb in all the real-life racing: Loёb takes #1 in WRC, and Alonso has to take something different.