Imho, the main reason why those in charge are not so easy with creation of new local board is because many of them are now either semi-dead or dead (take a look at Japanese board whihc was the last created before Nigerians got their own) so they want to be sure (as much as possible) that the same thing won't happen with new ones too. Regarding moderators assignment, I don't think that's an issue as some other local boards don't have their own and function pretty good even without it.
Quality>quantity.
Yes that's no doubt the primary reason why are no local boards. Very recently there is Nigeria local board and they are doing fairly good since they have there separate local board (click the link below to see there stats for December 2022).
I would say stats of Pakistani community are also very decent to claim separate local board and it will be just a matter of time. And yes we need to focus on quality not the quantity alone.
https://bitcointalk.org/index.php?topic=5357434.msg61559466#msg61559466