Bob Lazar’s statement on Joe Rogan that has surprisingly hasn’t been challenged?

With so much out there about whether or not Bob Lazar is telling the truth, I haven’t read many or any calling bs on a statement he made on Joe Rogan. When he spoke about seeing the nine craft, he mentioned they were all different but “running on the same fuel source”. If what he is saying is true, how would he know especially when he said everything was compartmentalized and then he only worked on the sports model?