True, but just because the Russian's can't afford to build bigger ships atm ss means that their current ships are not worth looking.
It is not too hard to imagine a hypothetical war on China's periphery, unthinkable yes but not impossible with all the current tensions going on. In those scenarios, a upgraded Type 56a can do more than just being a patrol vessel, such as a mobile land strike platform, freeing up larger vessels for more pressing matters. It would be a monumental task for an enemy force seeking to destroy such vessels hiding in China's shore line lobbing cruise and anti ship missiles.
Another factor to consider is future forward deployments, it is all but certain that China would be expected to deploy a forward military force in outposts like Gwadar and Djibouti. As such a cheap corvette that packs a sizable punch is a good choice for a force multiplier without having to deploy larger and more costly ships unless absolutely necessary. One only needs to look at the US navy to see how it is struggling to keep up with its commitments when it only can deploy full size combatants all the time.
And finally ,there is the simple reason of ''keeping up with the Joneses'', a little banal yes but it makes sense. In the near future, China can expect its neighbours to deploy UAVs for maritime patrol and warfare, such drones are cheap, stealthy and can pack a deadly punch if need. As such, the Type 56a will need to be prepared to face such threats on a regular basis as it would be the go to vessel for China for day to day interception and such. In these scenarios, the Type 360 radar and the 8 cell HHQ-10 will not cut it anymore.
The 56a is the ship of today, but it certainty is not the ship of tomorrow.