Good question. I don't have enough information to provide a definite answer, and nor does anyone else so far as I am aware. It would strike me as odd, however, if PLAN's first modern blue water frigate, designed in the very early stages of the 21st century when PLAN was still overwhelming focused on operations within the first island chain, in fact turned out to be ideally suited not only for operations in the second island chain and eastern IOR, but deployments even further afield.
The 054 was patterned after the La Fayette class, which was probably the first true modern post Cold War stealth frigate. At this point, it was the French who started the Euro-Frigate concept trend, that envisioned a ship smaller than a destroyer but is blue water, which means it can operate independently away from its home port for a long time, and is highly multi role, and not just an ASW escort. This was a return to the classic concept of the frigate in the Age of Sail, but in a modern context --- a single gun deck ship that is capable of being ocean going; the single gun line separates the ship from multi gun decks lines (ships of the battle line) and sloops (analogous to a corvette) that are still tied to a home port. In the modern context, the smallest unit of warship that is capable of operating in blue water and independently from its home port for long periods of time.
After Taiwan bought La Fayettes (the procedure of which since has become a case of criminal corruption), the PLAN was quite impressed with the ships (or feared) across the straits that either a counter or their own version was required. The 054 was born there.
This isn't to say the previous Type 053 wasn't ocean worthy. The basic design is sound; what was questionable was the pre-2000 shipbuilding quality of Chinese shipyards then, along with the lack of safety measures. But when that was accomplished even the Type 053H3 and its export variants proved to be fine ocean going ships. The Type 053H3 did participate in Gulf of Aden operations, and the export F22P participated in rescue operations in Yemen.
Obviously tonnage is an index of capability and not itself the characteristic of interest. Nonetheless, it is a good guide. If you want to put more capability on the 056 hull without sacrificing other qualities, then it is going to get bigger. If you want to increase range and endurance on top of that, it will get bigger again. These are reliable relationships.
Not completely. The Admiral Gorshkov class and the Korean KDX-II class are both 4500 ton ships standard but are as equally heavily armed or more so than many 5000 to 6000+ frigates. The Gorshkov class has a 5" gun, 16 cells for UKSK VLS and 32 cells for Redut. The KDX-II started with 32 MK. 41 VLS cells, but then added another 32 VLS cells of Korean design with Korean missiles. The 32 Mk. 41 cels are all strike length (7.7m) meaning they can do Tomahawks, and the 32 K-VLS is capable of firing an antiship and cruise missile analogous to a Harpoon. Both these vessels are more heavily armed in offensive potential compared to European frigates not to mention destroyers.
Of course the typical snide reaction, especially among Western European defense watchers is to denigrate the Gorshkov as "cramped", and if that is the case, the 64 cell KDX-II should be absolutely claustrophobic.
As for the Type 056, going to a 1800 ton C-18 or P-18 design means adding 300 tons for a second hanger and space for four more antiship or Yu-10 missiles. That is a significant jump in capability. Adding an SR2410C phase array on top will greatly enhance its sensor abilities for no difference in weight.
The Korean Daegu class frigates, starts at 2500 empty to 3500 full roughly, already sports a 16 cell K-VLS and 4 ASMs. Naval Group's FTI frigate is going at 4,200 tons with 16 VLS cells, but with 8 ASMs. However, the FTI's cells can only house the Aster 15, which means only the 4.3m deep version of the Sylver, while the K-VLS cell could hold an ASM analogous to a Harpoon.
The increasing trend right now in modern warships is cost and efficiency. Requirements are now being set with a budget amount rather than a weight. Type 31e is given a 250 million Pound figure. Doesn't matter if you build a 3500 or a 4500 ton frigate, it needs to fall into that budget.
