Let's not complicate it so much...
Dude... So far this system works in this way:
Interaction means that one account attack another
If there is interaction (attack) between 2 accounts that have an IP match (even in their history) that is considered cheating. That's all. Cookies also can count, but in that case they must use the same computer with the same browser and without deleting them before...
Anyway, i don't know if computer name is considered proof or not, looking that it also goes with http request.
Everything else in regulation is bullshit. All the rules there can already be deleted and replaced with the above one, because is the only one that really works.
Regards!