I'm pretty sure that Comms Attack is something that Attacks Comms Equipment. While there could be overlap that Comms Equipment is perpetrating Comms Attacks (Hacking for example), that does not have to always be the case. Game terminology does actually fit as a Jammer is a Weapon, not Equipment hence bypassing the second characteristic of your reasoning.
It's Campaign: Paradiso, because that's where the Jammer and revamped E/Marat appear. Helpfully, the picture is clearly labeled as both a Jammer and an E/Marat. I think the real question () is why the Heckler and Zulu don't have access to the E/Marat firing mode.
I figured for the purposes of this conversation it was best to go back as close to the source as possible.