Is the Prophet Salaamu Al-A'alayhi Wa Salaama a Copy of the Previous Nations?

The hadith was narrated by the Anusahi Hain, Buhari and Muslim. It goes on to say that our will not be established until my Ummah Ummati,. as in the Prophet Salaamu al-A'alayhi wa Salaami. My question is that the whole of his Ummah are going to end up copying the previous nations. How do you reconcile that with the fact that we also know from another hadith that there was always going to be part or a group from his Ummaha that is upon the truth?