Muhammad bin al-Hanafiyah once asked his father (Imam Aliy) about Abu Bakr and Omar, he said: I asked my father who is the best of people after the Messenger of Allah (Peace be upon him)?

He said: “Abu Bakr”. Then who? He said “Then Omar”. Then I was afraid he would say Othman, I said: then you? He said: I’m just a man from the Muslims. Related by al-Bukhariy in his Sahih.

If Imam Aliy affirms the status of Abu Bakr, Omar , Othman & Prayed behind them, so why argue?

Imam Aliy let his daughter marry Omar,& who named his kids Abu Bakr, Omar & Othman as al-Hussein did, he also named his children: Abu Bakr, Omar & Othman. And Imam al-Hussein named one of his sons: Abu Bakr, this shows their great love to the companions.