There are no NEC rules regarding the number of 'sub panels' or overcurrent devices that can be supplied by a certain size service or feeder.
The only thing that matters is the calculated load.
Wire a house that has 100 outlets, put 10 on a circuit and you end up with 10 breakers.
Now wire the same house but the owner wants each outlet on a home run. You would have 100 outlets with 100 breakers but the calculated load would not have changed.
