Answered by Ustadh Tabraze Azam
Question: Assalam alaykum,
Can two people late for the congretional prayer pray together at the mosque?
Yes, this would be permitted as long as the prayer doesn’t resemble the official congregational prayer of the mosque. Practically, this would be achieved by praying away from the prayer niche (mihrab) and without a call to prayer (adhan).
[Shurunbulali, Maraqi al-Falah; Sarakhsi, al-Mabsut; al-Fatawa al-Hindiyya]
And Allah Most High alone knows best.
Checked & Approved by Shaykh Faraz Rabbani