Colby's wrestling is good but overrated. He got taken down multiple times by LW RDA and was badly outwrestled by Usman (1/11, officially 0/11 on TD attempts).
He won't be able to wet blanket somebody like Chimaev who is far bigger and stronger than most of Colby's opponents.
Actually no, he did not get "badly outwrestled" by Usman. They both arguably scored 1 takedown and Colby had more control time. Colby has 72% takedown defense, (Compared to Burn's 47%) which would make him among the best defensive wrestlers Khazmat will face. However, people act like he will be completely helpless in grappling exchanges.
And it is doubtful that Colby would attempt to "wet blanket" Khazmat. What brought you to conclude that this would be his gameplan?