PLA advance in anti-ship missile

Sino development of these missile are significant for several reasons:

1. The Chinese knows that given the size of their economy, they cannot match American ships in terms of technology, quantity, quality, and training.
2. To ensure that they will not be humilated again, like they were in 1996 during the Taiwan missile crises, they made a concious effort to allocate their limited resources strategically. One of the decision they made to defeat or to neutralize American ships (and American carrier group in particular) was to invest in sophisticated anti-missile systems.
3. The Chinese had clearly made great progress in the development of these weapon systems. In any new conflagration over Taiwan, any American carrier group would have to take seriously into account these missiles.
4. The Americans will also have to take into account the extra-complication of PLA submarine force (like the one which surfaced within torpedo range of an American carrier group), and the PLA new jet fighters flying from unsinkable land bases.

Published specs are often over-stated or under-stated.

When a manufactuer claim the missile has 50km range, it often means 50km under ideal conditions. Actual combat conditions may reduce the range to less than half that.

During the Falklands war, the Argentine AF sent a high-altitude learjet to look for British navy ships. Technically the learjet was flying above the range of the Sea Dart, but it got shot down by a Sea Dart anyway. The Argentine pilot prolly thought "ok, I'm flying above their missile's reach according to these specs..." while the British chuckled and pressed the fire button.

If the PLA exports C-602 with 280 km, I'd expect the range specs to be over-stated (under ideal conditions only) or downgraded, while PLAN's own version has superior specs.

It's also possible to increase existing missile's range via upgrades. New rocket motor, fuel, computer controls, etc. The original Harpoon SSM's requirements called for a 45-90 km range missile. Today the latest versions have 220km-300km+ range.

Back in 2002 there was a report on a japanese newspaper that a DF-21 was succesfully testfired with MIRVs () but I couldn't find anything further on that. I'd be interested what was made of that. And last paragraph of link.
Now could it be possible to fit every single warhead with a seeker (FR/EO) so that it can find a ship from above when deliverd to the vicinity of a CSG. With their very high speed they'd be difficult to intercept and could punch right through the deck of the targeted ship before exploding.

And for the conventional AShM, what range has the seeker of lets say a C-602 ? And can therefore the reason of the 300km range restriction be due to the lack of target position update capability ?
The C-602 is said to achieve M0,9. That means it takes the missile a good 16 minutes to travel 300km. A group traveling at 25kts would travel 6,8nm or 12,6km in that time.