Some of these people just coming in, tapped on the shoulder of one of these people (who were from the previous Jamaat, and are now making up their missed Rakaats), and started a Jamaat behind him, with him as the Imaam. Is this the correct way? Alternatively they could have started a new Jamaat in the back, but they chose the former way. Is this allowed maybe according to some Madhabs?
It is not permissible for the Masbooq (one who joined the Imaam late) to become an Imaam for others when he is completing the missed Rakaats. (Fataawa Aalamgiri part1 pg.92)
and Allah Ta’ala Knows Best
Mufti Ebrahim Desai