“It says “hevi Dan es kol hudum lchaf zechus” it doesn’t say anything about brother”
it’s poshut, judge on the scale of merit means he has merits and you could judge him either way
if he is not frum he doesn’t have merit
we cut the non-frum way too much slack
you want to keep shabbos, we’ll help you
but if you don’t you have no credibility