Interesting video, it seems the factory only produce rocket engine and it does say 1000 per day. Very modern factory I'd say
Engine car manufacturer is normal to produce 1000 engine per day
But I doubt that China has capacity to supply solid propellant for 1000 cruise missile per day (currently)
I think the biggest bottleneck for any missile is probably the electronics and the engines. In any manufacturing process, all bottlenecks are identified and the entire capability is based on the bottleneck production rate.
In this case, saying 1000 engines a day basically means 1000 missiles a day. Electronic manufacturing in china is a no brainer for capacity. Fuel is not an issue, kerosene is jet fuel, what the military uses is a drop in a bucket to civil usage. The grade is different but only minor changes needed in the refinery to produce.
All other parts should have more than excess capacity and can be converged from civil manufacturing. Engine is in the only part not easily convertible. This is why 1000 engines a day = 1000 missiles a day from this factory. Or whatever downstream factory attached to this one
