You made it a point to mention their single fight in common - Heath. It took Lesnar 3 rounds and still didn't finish him, where as Fedor beat him very, very badly and the doctors had to stop the fight at the end of the first round. Huge difference.
As far as people Fedor has beaten, a prime Mirko would not only knock Brock's head off striking, but his TDD was extremely good, much like Liddell's was at LHW.
Arlovski would definitely beat Brock standing (technically), but the ground game would be all Brock.
Nog could/would get the better of exchanges on the feet, and on the ground he has great subs off his back and is very experienced, so I could definitely see him subbing Brock.
Other people on his list: Randleman, Coleman, etc, are mainly wrestlers but smaller than Brock, so it would be the classic "big wrestler vs. small wrestler" where the big one wins.
If they are all in their prime - Mirko, Nog, Arlovski (maybe). Others were wrestlers which would not fair well against the bigger wrestler in Brock.