A lot of insurance companies these days insist that cars have a certain minimum number of immobilisation points before covering them. I know Famous & Classic requires 3, which is why quite a few of my friends in S15s (that only have 2 from the factory) had to get aftermarket alarms.
Where the 3 points are is beyond me; I assume that fuel and ignition are two points (they're the most common). Perhaps they separate "ignition" into separate battery and starter motor cutouts.
The Brant Nemesis I have apparently has 6 points - I can't for the life of me figure out what else you can cut out aside from fuel and battery power. Its not like its designed specifically for throttle-by-wire cars, so you could put a cutout there.
I think their count is a bit "creative"; the only difference between the 5 point system and the Nemesis is the keypad, which I can't see "cutting" anything out. It just adds another layer of authentication.