For a couple reasons: 1) Making Dog-Warriors immune to non-lethal ammo is both unfluffy and has large balance implications that it's not clear are addressed. It's unfluffy because Flash/Stun weapons are used in-universe to deal with Dog-warriors - it's why Loup Garou have them. And it's got balance implications, too, with respect to Flash pulses and Stun rounds previously being very good ways to stop them, and now being disallowed, along with E/M and Monofilament. (And the E/M makes even less sense, considering it's presumably supposed to be blowing out the doggo's non-TI radio.) 2) Incredible durability added to the Karakuri and Sun Tze profiles. They don't have any vulnerability skills, and in the case of the Karakuri this comes along with an incredible boost in toughness from a functional ARM 3 to ARM 6. This puts the Karakuris in the place of being more durable than some TAGs, and far less vulnerable to Possession and E/M, all for dramatically less points. Sun Tze's in a similar boat. If they actually had to pay points to reach their ARM 6 they'll be using, they'd be prohibitively expensive. I don't really have much of an opinion on the change as applied to Überfallkommando or Symbiomates, as those are separate issues. Long story short, Total Immunity should have no impact on non-lethal ammo, and they should probably consider adding Vulnerability: Monofilament to all the models with extant TI (though perhaps not Symbiomates; personally I'd remove the fire vulnerability from symbiote armor and add it to symbiomates). Also, a TI user should only be able to roll BTS vs. attacks that target BTS to begin with (Plasma, Viral, etc).