Smaller Burns and Shorter Usman were able to counter-grapple Chimaev. Both ended up striking quite decent in those fights, but still lost.
Smaller, shorter Tsarukyan was able to counter-grapple Makhachev, but still lost.
Shorter Volkanovski did okay in the first fight against Makhachev, but still lost.
Sometimes the smaller and/or shorter fighters are better at counter-grappling these elite grappling gurus.
Topuria might be the one that finally solves the puzzle and get the KO.
But Makhachev is quite precise and good with striking. He could use his grappling threat to set up Topuria and get the KO instead.
(Martins got nice knockdown on Islam and win. But that was an early stoppage by the ref. Islam was still ready to fight and defend. I hate early stoppages.)