Andrews. A frigate with less complicated systems needs less ranked crew aswell.
The total cost picture of a Frigate is waaaaaaay lower then a Destroyer.
For example, dutch zeven province frigate (actually destroyer) has a crew of 30/40 weap tech (sensors. weapons. comms etc).
and a karel doorman frigate has 20 at most.
From those 30/40 are 3 officers and 4 serg majors. 20 corporals and 4 a 5 sailors.
Frigate has 2 officers. 2 serg majors. 10 corps and 6 sailors.
Not speaking of the tech section and the rest aswell.
You need more administration and cooks for all the crew and stores onboard.
Also fuelwise,logistics is bigger.
Maintenance is more costly.
When something breaks on a destroyer is also more expensive.
Then 052 to 055 it will be the same as 054a compared to 052.
But you can also think...
More modern systems is more automatic.
Bigger ships barely need more sailors for nautical stuff (mooring, painting etc).
Bridge crew is the same.
Comm center a bit more (officers rates are almost the same as smaller but still full weaponised ships).
I dont know how China currently operates on crewwise and future of automated systems...
In the dutch navy we got apar and smart-l.
Both when they where new, had big expenses on maintenance.
And both need a large cooling system, especially in high temp sections of the ocean.
Just 20 cents i wanted to add to haha.
I can talk hours on in this discussion. It all depends on how the navy operates...