You forget an important part of their culture was that though majority of Mandalorians are portrayed as humanoid, they took in all species that could prove them selves warriors. There are Ithorian mandalorians, rodian, chiss, humans, etc. Taung were just the originals and that culture was adapted by other species they assimilated into their culture. It's all about who is the best warrior, not the color of your skin or species. Old or New, they are essentially the same, just varying degrees of aggression.