A winner of major handicaps on the level and good enough to be runner-up in a Champion Hurdle by employing front-running tactics, there have been rumblings the way to upset the nine-year-old is to challenge him up front.
But McCain does not see that as an issue and believes nothing will be able to live with Overturn over the first few fences.
He said: "I don't think anybody needs to question the way Overturn is ridden.
"I keep reading about horses that are going to take him on, but he's led Chesters Cups, Northumberland Plates and Champion Hurdles so I don't see why anything should change his way of racing.
"If something wants to go quicker than him, get on with it and good luck."
Looking to tomorrow, Cool Operator is well equipped to take on what will be a big challenge in the Eider Chase at Newcastle.
Heavy ground is assured but that is unlikely to deter Philip Kirby's 10-year-old, who looks like he thrives on a stamina test.
Faced with a trip in excess of three miles for the first time at Carlisle in December he gave the impression he relished it, powering clear to defy an 8lb rise for a Uttoxeter win well advertised since by runner-up Rigadin De Beauchene.
Well thought of as a young horse when trained by Howard Johnson, and even running in the Arkle Trophy at Cheltenham, he has a further 8lb hike in the weights but this four miles could feasibly see further improvement.
Finally, the QTS Group has been named as new sponsor of the Scottish Champion Hurdle at Ayr on April 22.