I don't think you are being realistic in your views.....possibly if the 3-point shot had been in place at the time of Byrd or Lee, etc. their record would be very hard to break....at least IMO.
Another factor no on is considering, too, in those day, teams played a LOT LESS games!! Barely 20 during the regular season. Not very many non conference games, in season tourneys, and NCAA and NIT fields were much smaller. No "lesser" post season tourney play, either. Players today can play more games in 3 seasons than players back then could get in four. Then, too, freshmen were NOT eligible to play varsity ball, so 3 seasons with fewer games was it!!