Just a heads up if somebody else is checking the bf2 server:
I did find 3 others with linked guids, Hardkor95_PL, enemyufo.cz and merechy - but I could not establish a clear link on none of them. Enemyufo.cz has 168 linked guids, but there was no match by IP, or by alias. However, there is one ban on the same IP that he was playing on our server - but for COD4.
I went in and scoped enemyufo.cz and merechy - both clean players. Hardkor left before I went in. I scoped enemy for like 10 min and he is not hacking. He seemed a good team player, reviving etc. Yes, the ban on COD is damning, but it could have been somebody else playing on that IP. I took no action on all 3.