If the din were at the Pleiades, even then a person from Persia would have taken hold of it, or one amongst the Persian descent would have surely found it. (Using translation from Muslim 2546a)
قَالَ رَسُولُ اللهِ ﷺ لَوْ كَانَ الدِّينُ عِنْدَ الثُّرَيَّا لَذَهَبَ رِجَالٌ مِنْ فَارِسَ أَوْ أَبْنَاءِ فَارِسَ حَتَّى يَتَنَاوَلُوهُ