Haven't played much Impostor post-MKXL but I think Spec Ops could be closer to 5-5. Her having access to a counterzoning tool (however mediocre) is good for slowing Impostor down, especially when his full screen game is a little lacking. Her also having ways to get through hellsparks (if spaced properly) like B1 and being able to anti-air him out of teleport pretty well also give him problems but as you say he has access to 20% chip strings lol.
I also think Cybernetic Impostor is 5-5.
I'm not sure about him losing to Covert Ops, mind going into a bit more detail about that? Demo sure and Special Forces maybe but Covert Ops has a hard time getting in against hell sparks I feel.
Funny coming from the man whose justification for pre-patch Quan was "don't get hit"