I had a theory that goes like this.
Traditionally, the J-8 and J-8II units are the ones considered elite. They also got the Flankers first.
When the PLAAF began to enact their own equivalent to Top Gun and other dogfighting programs, they discovered the J-7 units were owning the J-8II units. They also discovered the Flankers with the former J-7 pilots were also owning the Flankers flown by former J-8II pilots. To make matters worst, the J-7 pilots on J-7s were also owning the Flankers flown by J-8II pilots.
Since then, J-8II units stopped Flanker conversions and all Flanker conversions focused mostly on J-7 units. When the J-10 came, they too were focused on all J-7 units. J-8II units were upgraded to the J-8F instead.
The 44th was a highly regarded J-7 unit. Good pilots but badly in need of new planes.
One notable exception was the 24th Division, which soldered on with J-8Is. I mean first generation J-8Is! They managed to keep their old birds well maintained, flyable, and developed an impeccable record for safety and high readiness. Without any BVR, these birds also forced pilots to rely mostly on their WVR skills. In my opinion, they deserved their new J-10s.
As much as there is a strategic system involved, the merit system is also deeply involved in the J-10 allocation process.