Why no China?

[Legbreaker]

Yes, I just can't see the Chinese nukes being a credible threat to the Soviets given the history of the war to date and clear advantage the Soviets had with satellite surveillance.
You can bet any silos would have been identified early and targeted with the first wave. Satellites and other resources would certainly be focused on the mobile launchers with strikes occurring the moment they were exposed.
Strategically, Chinese nukes are only likely to be of much use in a first strike, surprise situation. In T2K they had no chance to get more than a handful off the ground, and as written in the timeline, the Soviet ABM system was very effective against them.