Umar Ibn Saad, Ibn Ziyad (who is also glorified as a man of power!), are also considered thiqa by Sunni scholars of hadith such as Imam Nasai, Asqalani etc.
that is strange...........brother why did Bukhari who lived during the same time as imam ali raza, imam ali naqi, ali hadi and ali askari did not take any narrations from them? specially the 8th imam since he was widely known in iran, place where bukhari hailed from?