An interesting observation, and possibly a sign of changes that might be on the way in 11th (Apologies if this has already been discussed).
Commissar Graves on Foot, in general, is a bit of a let down for me. She's more expensive than a Castellan, her order set is still restrictive, though somewhat improved from a standard Commissar, and we seem to be paying a premium on points for her ability to clobber people in the Fight Phase. Whatever, she's a nice model.
But hang on a second, may attach to COMMAND SQUAD.
I double checked, this doesn't appear to be some sort of weird typo, there is in fact a comma after CATACHAN JUNGLE FIGHTERS, so this means that she can be attached to a Krieg Command Squad, rolled into a Death Korps squad of 20, with Commissar Yarrick, AND Nork Deddog. Is it good? Probably not, but it IS 29 models in a single unit, and an unholy amount of actual real melee attacks.
More interestingly, could this be the moment that we see all our Ancillary characters be able to join our Command Squads, like attaching a Primaris Psyker to the Cadian Command Squad, so we don't have to lose out on the Castellan, and have a 300 point murderball with a 4++ save at range?
I'm not sure how good this will end up being, but it could open up some interesting directions for us. I personally am a fan of a Krieg Murderball with a Primaris Psyker and Commissar Graves that's able to soak up firepower, weather a charge, then Fall Back, Shoot and Charge. Is it good? No idea, but again, it sounds like an interesting possibility.