Liquid fuel is way better for a silo-based system than it is for a mobile or sea-based system. Ampoulisation and other measures reduce the downsides of liquid fuel, while its much higher energy density enables greater payloads for the same size of missile compared to solid fuel.5C is liquid fuelled? So not a good choice for a silo-based system.
My understanding was that DF-45 is the silo-based version of the DF-41?
But my point is that if China has no plans to put 10 warheads on each missile, they might as well use a smaller and cheaper DF-31 instead.