Does NS4/NS5 contain passages that will SPOIL AAMC sample exam/FL1?

I have taken NS1-3, and have read around and I think I recall people warning about doing NS4/5 BEFORE the AAMC exams because apparently there were passages from those exams that were very similar to the AAMC materials?

Is that true?

Also, how do NS4/5 compare to NS1-3 and other exams?

Thanks!