Arso: rereading your post- please show/ quote me where Ispashtusa dMoshe is in the plural (besides for the fact we all have a spark of Moshe within us, I know that. As well as a spark of Moshiach, Navi etc.)
But from what I learned, there’s the mini version in all Yidden and the macro version in the Rebbe.
It would seem from rashi I think it is – Shmuel bdoro kMoshe bdoro etc- yes there were many leaders I’m sure, but one was highlighted as the go to for the generation