For anti-shipping roles, wouldn’t a 30-knot+ arsenal ship with large number of anti-ship missiles (cruise and ballistic missiles) and CEC makes more sense?
055 class are equipped with very expensive sensors that are geared toward anti-air and anti-space. Those expensive sensors aren’t used for ship searching. UAV, KJ-600 and space assets are the one that hunt down the locations of enemy surface ships. It would be a waste to put so many anti-surface missiles on 055.
CEC = Datalink between ships that are line of sight between the antenna of each other. The immediate transfer of data is fast enough between the ships that it can be used to track airborne targets for an air defense function enabling an air defense umbrella encompassing all the ships that are interconnected.
For antiship its a different form of networking, one that encompasses communicating with satellites and airborne assets, e.g. AEW, MPA, helo, MALE and HALE drones. For ASuW purposes you need to capture data from beyond the horizon. Actually for ASuW, the sensor investment isn't that high. With PLAN warships its usually in the form of the Type 366 antiship targeting system that's a kissing cousin to the Mineral-M systems used by Russians and the Ukrainians (Moskva is said to have been targeted by the Mineral-U). This system physically appears as a dome over on top of the bridge of many ships, as in the Sovremenny class, the Type 054A, 051C, 052B, 052C, and 052D, and as the main radar for Russian corvettes, such as the Tarantul class. The Mineral system was first introduced to the PLAN with the Sovremenny class, and since imitation is the best form of flattery, the system is copied as the Type 366 for domestic PLAN warships.
It consists of.
An active X-band radar component that rotates. This has a range of up to 250km. The difference beween the PLAN Type 366 over the Soviet era Mineral is the addition of the ability to detect low flying objects for the PLAN radar, giving it an air defense layer.
A passive radar component. The Mineral or Type 366 radar consists of two antennas mated back to back. One antenna is for the active radar, the other is for the passive radar or ESM. The second antenna deals with a wider range of wavelengths from L to X-band, which essentially detects the radio emissions of other ships, geolocates them for antiship targeting.
Both active and passive radar systems use a method called Atmospheric Ducting, in which radio waves are reflected by thermal layers in the atmosphere, a phenomenon as it turns out, conveniently strong in the Western Pacific.
A datalink component. This takes the shape of either a small globe shaped dome, or a small R2D2 shaped dome. This datalink is usually found near the middle and around the funnels of the ship. This datalink takes data from airborne sources. For example, there are two port and starboard of the aft mast near the 054A's funnel, two underneath the Type 517 VHF arrays on the 052C and 052D.
Whereas the other two components are fairly large, it is the datalink that is conveniently small and only requires a low investment. Ever wonder how a Type 056 can target a ship over the horizon without a long range antiship targeting radar with those 200km+ over the horizon YJ-83s? The ship has two domes in the rear deck, the larger one is a SATCOM, and the smaller one has to be a Type 366 datalink.
While the Type 366 is probably the first system in the PLAN in place for OTH ASuW targeting, there is no doubt that a more sophisticated system involving satellites are taking its place, but for the sake of legacy and redundancy, the Type 366 remains. At least, up to a point, since its gone with both the 055 and 056. What remains still is the last portion, the datalink, because of the small investment this requires. In the Type 055, I believe there is a small dome right on top of the bridge that best fits the description and size of the 366-2 datalink, usually shielded from view by the bar shaped arrays on top.
The OTH networking for ASuW targeting should be transferred to the much more modern SATCOMs and the satellite systems they communicate with. For passive targeting, it should be transferred to the ESM systems, namely the kebob like ESM mast on top of the integrated mast, and the two R2D2 shaped domes near the base of the integrated mast. Like the datalink, the ESM systems are a small investment in terms of volume and weight.
With the Type 366 system no more on the 055, with only the datalink, its a question if the active OTH radar function is ever included into the AESA panels. If it does, its likely on the small X-band AESAs on the integrated mast and not the giant AESA arrays on the superstructure which is for air defense.
To put it in another way, the 052C/D and even the 054A may have a better antiship detection suite over the 055 thanks to the legacy systems that are not fully replaced on the 055. The SATCOMs on the older ships are the same as on the 055, and the newest SATCOMs are all retrofitted on all ships equally, so satellite access for antiship targeting on all ships are equal. All have the same Type 366-2 datalink, so access to aerial sources are the same and equal. Where the 055 might have an advantage, is that it has a newer ESM mast which leaves the possibility that its passive detection and locating systems might be superior over the legacy systems. The newer ESM mast itself is not a high investment either in both room and weight; I can see it being used as part of a future frigate.
Even in the case that the Type 055 lacks the active OTH targeting accorded by the legacy Type 366 system, all the 055 needs to do is to network with a ship that has it, such as the escorting 052D, 052C or 054A. So in the end, the 055 can access as much targeting data for antiship as much as any other PLAN ship.
This also highlights the importance I see of small but high tech capability ships that can be used on the outskirts of the battlegroup, both to expand the air defense umbrella by CEC and to further the over the horizon ship location network. This is why I think a new small destroyer or frigate is important as a force multiplier for the 055.
An Arsenal ship, unless it is being used to support an air defense role, won't need CEC. But then again, CEC arrays is another small and cheap investment on its own, won't cost the ship much, and won't weigh the ship down, being physically a set of four flat fixed faces which you need to embed or hang on a mast. Its not a huge penalty to a ship to add it so let's just add it anyway. For anti shipping, the datalink to talk to aircraft and drones is a small investment; the ESM mast for passive OTH location is another low investment. If you want to bother using the entire Type 366 radar system on the arsenal ship, it won't be a huge investment either, since the Mineral is used as primary radar on small Russian corvettes. Then add the requisite SATCOMs, again, not very high investment items either.