He hasnt beaten anyone. If you choose to put him in the Top 10, it's entirely speculative.
For example, Overeem can take backhanded shots at Brock's mythical rankings all he wants, but Brock has the better resume. Show me the Overeem wins over the caliber of fighter Brock has beaten. They don't exist.
Couture/Carwin/Mir > Rogers/a bunch of bums, by a mile.
If Overeem wants to prove himself to be a legit Top 10 in his division, he should stop playing footsie with the kickboxers, step in the cage, and beat some people. The only reason he's considered a Top 10 guy is because heavy is so shallow, it's not ridiculous to leave him out (I wouldnt, he'd barely make mine), HE HASNT BEATEN ANYONE.