It seems that some think that if CAC is limited by its size of workforce and floor area to meet PLA's demand, then it must be SAC to produce large number of J-35A to fulfill that demand. However this is not the only possible conclusion to draw.
It's not the only conclusion, but it should definitely be the most likely conclusion/explanation to explain what we are seeing.
I tend to think CAC and SAC as a whole, they together fulfill whatever demand that PLA want. What ratio of J-35 and J-20 is up to PLA's design of their force structure, less a thing based on who is designer and producer. If hypothetically PLA only want heavy fighter or majority of their fighter being heavy, and CAC's current manpower is inadequte, AVIC can alot floors and workforce in SAC to produce J-20, or sent workforces to CAC if factory facility isn't the limit. AVIC's former self did that many times, XAC and CAC were created out of SAC and CAC got the job of making J-7 that was initiated by SAC as a result.
This has already been discussed previously, either in this thread or others.
There are likely multiple reasons why the PLA has chosen to pursue J-35A alongside J-20/A rather than just increasing J-20/A production itself.
One of those reasons could be timing and ease of scaling up -- that is to say, it is actually easier and faster for them to get SAC to scale up J-35A production capacity than to have CAC scale up J-20/A production capacity or to have CAC teach other organizations to build J-20/A of their own, and any combination of "building more J-20/A production capacity" is unable to meet the PLA's timelines for 5th gen airframe demands while also allowing CAC to preserve its ability to carry out all of their other production, R&D, etc.
Other reasons that are important, of course include that J-35A is able to meet the PLA's requirements in terms of capability and likely having lower cost due to being a newer design with some newer production technologies than what even J-20A is able to integrate. Then there are military wide benefits of having J-35 and J-35A both exist and able to share common suppliers/upgrade pathways.
So I won't put much trust in the talking by the Guancha Trios of "CAC up to their extrem limit". They know some bits and pieces from their contacts here and there, but not every dots can be connected correctly. Even they know a guy in the production line of J-20, that guy won't necessarily know what AVIC and PLA have in mind.
I certainly don't think they should be treated as gospel.
However, I do think the idea of "CAC reaching their organizational limit" wrt J-20/A production is also a logical explanation that we should have been able to arrive to independently in terms of explaining why the PLA had adopted for J-35A + J-20/A rather than just pushing J-20/A alone.