I do agree that the ISS is not usually considered to be a communications satellite (though it does have plenty of communications gear on board, including a ham radio repeater if I recall correctly). But it is a thing that we might want to deorbit one day. Since we were considering the ridiculous closing velocity of two objects that are both on escape trajectories, I figure using the ridiculous mass of the ISS was fair game too. But like I said, I originally guessed 50t, not 400t. I was thinking more about the payload capacities of launch vehicles than the satellites themselves.
Whatever mass and closing velocity you consider, 7 or 10 or 11 orders of magnitude all qualify as “quite a few” even if the velocity itself only has 1.3 orders of magnitude of difference.
Of course you can make the statement true by changing everything it's about.