One of the things that make Padrinorca so over the top is how hard it is to find stun protection that doesn’t die to it, as I’ve said here:
Giving it Stun Killer would reduce the number of Orca-safe stun protection to 2: Bloomluga and Plumesilisk (which I hadn’t counted at the time because it was so new). That wouldn’t solve anything, it would just replace an issue with another.