That's not how it works. Even if/though others may not attack, they will still test the resolve of the Chinese when there's a war. So the Japanese, Americans, Russians etc will fly almost like they are also at war with China and put pressure on them to react. This stresses out Chinese logistics and provides others with long term advantages, including training.
The Chinese build 250 jets in each batch, so they can distribute 50 jets to each of their 5 commands. So it's not really a lot for each command. And central command acts as reserve, so jets from there can be reallocated as per need.
It's always the case, things appear bigger than they really seem. When you break down a large force into smaller chunks, you will notice that all big militaries all over the world are actually working with shortages. The US forces are also too small for their needs. Take the navy for example, unlike India and China that are dealing with 2 and 3 seas respectively, the USN deals with multiple oceans in multiple continents across the world. So their real world capability in a specific part of the world actually becomes very small. Their impressive 100 destroyers becomes just 12 destroyers in the IOR, 18 in the Western Pacific, 12 in the Eastern Pacific and so on. So China deals with the same issue when it comes to their air force, India does not.
If they feel 50 is not enough in each batch against India, then they will have to increase the numbers in each batch for the WTC. Or just increase the size of the reserve command so the strength of the WTC can be increased as per demand. Regardless it means the resources of other commands are unlikely to be transferred to the WTC due to pressur efrom other countries.
The numbers are sufficient anyway. If we assume each batch forms three tiers of advancements, ie, advanced, current and outdated, then 50 from each tier will be 150 jets. So 50 J-11A, 50 J-11B and 50 J-16 will give the WTC 150 Flankers with three tiers of advancements. Adding 150 J-10s will give them 300 fighter jets against India in WTC, which can be doubled using the reserve command during wartime. We will have 100 MKIs and Rafales in the NE and 160 MKIs, Rafales and Mig-29s in the North. With another 40 MKIs available to bolster either side.