You have some flaws When 2 Brahmans marry it is neither anuloma or pratiloma You are right when you say that many of DN Tagore s other sons had non Pirali brides This is also there in Sivnath Sastri s Histry book on Brahmo Samaj 1st ed at P 127 late Babu Haradev Chatterji father in law of two of Debendranath s sons Chatterji is one of the 4 highest castes of Bengali Brahmins and definitely not Pirali The difficulty in arranging Rabindranath s marriage was his associating with beef eaters and his loose early life Both Dwarakanath and Ram Mohan Roy had the same problem and used to employ 2 sets of cooks Muslim and Hindu which upset all the womenfolk in their houses