SOLUTION:
I think 10 are needed to fulfill the work of the saint and until Ischak was born Abraham needed to “convert” Abimelech in order to have a minyan that could replace him.
Sarah was attractive to Abimelech because he wanted to be holy. He later gave armed protection to Abraham. His merit made Zeresh (his great great grand daughter) Queen before Esther.
Odesser has a lot to do with ten and Rabbi Nachman said he could bring Messiah but preferred creating a minyan.
It takes 10 to carry the bones since the King is not eligible to do it. If this doesn’t happen the Messiah will do it alone!