Speaking of the utilization of A-shoot, B-guide during the recent aerial skirmish - Here's a rough map showing the PLAAF's KJ-500 radar coverage over the disputed regions between India and Pakistan.
The publicly-available claim of maximum range for the PLAAF's KJ-500 radar sets is listed at 470 kilometers. However, due to the high-altitude terrains of the Himalayan and Pamir mountain ranges and other possible factors (weather, EW etc), I downgraded the value to 350 kilometers.
All the KJ-500s are set to fly about 40-50 kilometers from the border lines.
As seen, most of the Jammu & Kashmir (J&K) and the entirety of Ladakh can be covered by the KJ-500's radar systems. There are only the western portions of the J&K that aren't covered, though I believe that one or two Erieye AEW&Cs operated by the PAF should be sufficient to fill the remainder coverage gap over J&K (of which the PAF operates 10 in total).
And then, there are also the following considerations:
1. The KJ-500 radar sets' coverage could in fact be greater than the aforementioned 350 kilometers, mainly because the KJ-500s are operating over the Himalayan and Pamir mountain ranges while looking down at the relatively lower terrain of northern India;
2. There are no stealth warplanes in enemy service in South Asia until the mid-2030s, at the earliest;
3. There are also the next-gen AEW&C aircrafts (namely the KJ-700 and KJ-3000) which will be joining PLAAF service within the next few years (if not already). Both the KJ-700 and KJ-3000 are expected to provide even greater radar coverage ranges than the KJ-500, as both of them feature larger dual-face AESA radar arrays than those on the KJ-500, among other improvements/upgrades; and
4. The addition on unmanned (and somewhat attritable) reconnaissance and AEW assets to the overall equation, such as the WZ-7, WZ-10 and (especially) WZ-9.
I suppose it wouldn't be an exaggeration to suggest that warplanes taking off from New Delhi could be spotted from the Chinese side of the border, either.
Hence, I don't think the importance of the implications of China providing assistance to Pakistan in its defense against India in this particular domain, despite China not being an active belligerent in the conflict against India can be overstated. It mainly depends on how well-integrated the data-sharing capabilities between the Chinese and Pakistani forces are, in this case.
