alt Hacker NewsThey did an n-body simulation based on the known Keplerian orbital elements. That's exactly what you're asking for, right?
Also, the formalism is the standard way astrophysicists understand collisions in gases or galaxies, and it works surprisingly well, especially when there are large numbers of "particles". There may be a few assumptions about the velocity distribution, but usually those are mild and only affect the results by less than an order of magnitude.
"N-body simulation" doesn't mean what it's normally taken to mean here.
And the colliding gasses models have the huge assumption of random/thermal motion. These satellites are in carefully designed orbits; they aren't going to magically thermalize if left unmonitored for three days.