The fanatics miss the point of the game being fun.
I had read the Tales of the Jedi shortly before playing KOTOR and recognized a lot of it in the game.
Actually it is technically correct that the Mandalorians were in allegiance with Exar Kun because Ulic was supposed to answer to Exar. Even if Mandalore didn't know at first who Exar Kun was. Because of the deception practiced by the three- Droma, Kun, and Aleema Keto, and how the war against the Republic was conducted, and the Mandalorians themselves being nearly destroyed, I can't see how the Mandalorians would have allowed themselves later to be tricked again or used by the Sith. They aren't stupid. According to clasical warfare there was plenty of reasons for the Mandalorians to attack the Republic again, which is where Revan comes in decades later. At that point the Mandalorians would see the Sith and Jedi as being two sides of the same faction and to get entangled with them meant destruction of their clans. Why they attacked the Republic later would be out of revenge, to make the Clans stronger, and simple expansionism as the new clans grew under the new Mandalore.
Well, anyways, not to derail this thread completely, can you imagine the Exile being a Hutt enforcer during those years of wandering? Hanging around places like Tatooine and being a smuggler?