Anyways, I'm not going to bother arguing with an idiot as he will just bring you down to his level and start insulting you....
Mandalore might technically join you if you are lightside because if you recall, in the EU, there were only a few mandalorians after ROTJ and they were destined to rebuild their once mighty civilization and became allies of the republic. Although this is approx 4000 years after KotOR, it is possible that this Mandalore would join your party and become a force of good but maybe get assasinated or something later on. Blow the theory to bits if you want
However, there is also an equal possibility that Mandalore is DS and wants to seek revenge on the Republic for what they did to his people but I strongly recall Canderous saying that he didn't hold a grudge against Revan. This is pure speculation as obviously the developers do not want to give us too much information. They simply want to wet our appetites.