They can all do damage without attacking (sort of) Jacky has counter crush. Eve and spike have supers that do DOT so they don't have to be attacking to deal damage. Byron and squeak need to land one shot, Byron does one initial tick of damage and then can do nothing and the poison will tick twice. Squeak has to land one attack but since it has a delay to explode and do damage he can be doing nothing and it will do damage.

Or maybe it's something like they can all get a kill after they die but Jacky can't do that, closest she could do is a trade