My gut says that a large part of these Rabbis most people have never heard of, forget respect. I don’t like how hiding their actual names behind the general title “Rabbis” gives them some form of clout.
Regarding the first one, I don’t know who is reading out the ‘Kol Korei’, but the Rebbes are; To the left, The Alexander Rebbe, then on the right, The Rachmastrivka Rebbe of Eretz Yisroel, The Vizhnitzer Rebbe Reb Yisroel, of Bnei Brak, (I can’t see who it is with his head down), The Machnofke Rebbe.