You are right, human/software part of military buildup is often the least appreciated part. The fact they are able to pump out this many j20s show that they have gotten much at getting pilots through flight school and from 3rd to 4th to 5th gen aircraft.
No doubt they'll be mass producing WS-15s the same way in a few years.
You don’t think the experience gained with WS-10C mass production will help them in scaling WS-15 mass production?, or that WS-10C lines could be upgraded to WS-15?It took 5 to 10 years for WS-10 production, post WS-10A, to scale up to this "mass production" rate. WS-15 would only be in initial serial production in coming years. Would take at least 5 or so to reach mass production rates similar to current WS-10B/C.
You don’t think the experience gained with WS-10C mass production will help them in scaling WS-15 mass production?, or that WS-10C lines could be upgraded to WS-15?
Either of those can shave years of your estimate.