frigates has its position in nearly every navy.it's a symbol when you send your ship to exclusive economic zone during peaceful days.While other ships can also do that thing,but frigates is a composite of fire power,cruising endurance and many other things
i dont know if FL3000N could be a replacement of HQ7 on f22p?
it seems affordable and reasonable.however i dont know much if FL3000N would perform better than hq7.BTW i can still see hq7 pics on land forces of PLA,which indicates hq7 to be reliable to PLA