It is not the hulls, or even the engines, but the whole system integration.Russia has problems building the hulls. If they don't like the engines or systems China uses they're welcome to order the hulls and ask for a customization, even ship their own systems over to China for installation. China already builds ships for Arctic service.
Same issue like with the Ford class carrier, or like Zumwalt.
Only difference is there is no 40+years ships designs filling up the production pipelines like in the USA.