They should just build 20 054B even if it is just a "transitional" design. Then build another 30+ whatever the new class looks like. This is how you build the world's largest navy when your shipbuilding industry prices are still affordable.
That's also how you risk block obsolescence, by poor planning.
It's not like their goal is to have the world's largest navy, rather the goal is to have a capable navy that is well balanced and able to achieve their nation's requirements.
Being 100 percent fair, 052D is a refreshed 20 year old design in terms of hull design and propulsion with the latest electronics/sensors and weaponry. 055 is cleansheet design but in terms of hull design and propulsion it still is relatively conservative for it's time with conventional COGAG and not IEPS etc.
On the one hand, that is true, but on the other hand it is somewhat ludicrous to suggest that a mature IEPS capability was ready for 055 considering construction of the lead hull of the class began in like 2014.
"Conservative" is in context of available technologies and subsystems, and in terms of propulsion 055 was certainly using available and ready prime movers and gearing configurations -- because as some other ship classes in the world have demonstrated, being overambitious or a bit risky with propulsion means you are at risk of sidelining your entire warship class if not careful.
The biggest problem with 054B is IMO with the conservative propulsion and hull design, not the weaponry and sensors. IEPS is still pretty new to China with the first navy vessel featuring it being the 076 and even that is still built with old turbine technology instead of the latest CGT-30 series which is still very new and unproven. AFAIK, China also lacks domestic large medium/low speed diesel engines, if I remember correctly the latest ones are only 6MW to 8MW max.
The external hullform of 054B is perfectly adequate. The question is more whether the internal compartments is able to be redesigned accommodate a more future proof propulsion train.
But as a CODAD frigate, 054B is fairly adequate and compares favourably to the likes of other contemporary CODAD frigates like Iver Huitfeldt, Type 31, FDI etc.
I think people should be somewhat appreciative that CGT25 has been mastered to begin with, and that they are in a position where they have a realistic near term/imminent pathway for CGT30 and CGT40 etc on naval ships.
There was a real possibility until the early 2010s that PLAN medium to large surface combatants might not have access to scaled, mature gas turbine production, and that they might have had to contend with steam turbine propulsion for a further 2 decades or so if various pieces had not fallen the way they did.
