This is a very interesting topic, but it doesn't attract much attention.
In modern times, the organization of the world's militaries is not entirely uniform, but it is mainly divided into the Western (NATO) system and the Soviet/Russian system. Of course, in earlier times, the two actually had many similarities. The former's primary focus was rapid response in small- to medium-scale wars, while the latter's primary focus was large-scale warfare.
Due to their different focuses, their weapon systems have undergone many subtle changes during development.
For example: how many fighter jets correspond to one ground maintenance unit? How many combat units can a command center mobilize? What is the scale of its corresponding logistical support system, etc.? This is a very complex and massive systems engineering project, not simply a matter of arbitrarily determining the number of fighter jets.
Generally, if country A purchases fighter jets designed and manufactured by country B, then adopting country B's air force organizational structure is the most efficient choice for country A. Its corresponding systems are optimally adapted. However, in reality, this is usually unlikely. Therefore, when exporting fighter jets, producing countries typically make adjustments to their maintenance and support systems to suit their customers. But the optimal parameters remain those adapted to the country of origin's organizational structure.
South Asian countries generally use Western organizational structures. Therefore, 20 J-10CEs constitute a basic unit. The Uzbek Air Force uses a Soviet/Russian organizational structure, and the PLAAF itself is a derivative of this system. Therefore, the Uzbek Air Force procured 24 J-10CEs as a basic unit. This is completely consistent with the PLAAF's organizational structure.