My reply is general, quote below is only for context:
The advantage of type 075, besides it size, is the flexibility of deploying troops on shore. It has helicopters and LCAC for high speed assault on the beach front as well as insertion of troops further inland from the beach front, and it can do commando raids as well. The speed of helicopters and LCAC also means that if the original planned landing site is too hot, they can quickly move to alternate landing site with little time loss. This is where type 072 is not capable of.
Financial cost is not an important consideration in initial phase of beach assault, human cost has priority. After establishing a safe beach front when transportaion of materials and reinforcement will be carried out in earnest, then cheap transpor ships (i.e. low financial costs) will play their roles.
In short, type 075 and type 072 have their own role to play, and they should not exclude each other.
This kind of speculation should be grounded in proper study of amphibious warfare:
The purpose of a landing is to establish a secure logistical base for sustaining operations in hostile territory. All other purposes are secondary and the previous USMC doctrine (Expeditionary Force 21) involves staging of combat operations at sea and at large distances from enemy territory until a logistical base is established,
ideally by capturing an existing port facility.
An opposed landing occurs when deployment of forces in hostile territory is actively contested by enemy forces. The kind of deployment or enemy response is irrelevant. While unopposed landings are preferable most landings today would be opposed landings because how technology affects space and time constraints. In WW2 many landings were unopposed for that reason.
Beach assault is a specific term for capturing a defended beach which indicates that no other point of entry and no staging ground on the shore are available. It is the worst tactical scenario and is to be avoided at all cost. Most of post-WW2 doctrinal development - including the LHD concept - stems from the
need to avoid beach assaults.
The primary role of a amphibious ships is to transport force from point of departure to the landing zone. Combat deployment is only the secondary purpose. LSTs were invented due to lack of infrastructure.
Expeditionary Force 21 concept illustrates it very well:
Amphibious operations are all about establishing logistical networks. Once those are established "amphibious" becomes ordinary sea transit. There is no need for large amphibious force if shore-to-shore logistics is secured. The side with overall advantage (air and naval esp.) can take its time.
Note two things:
- "seize advanced base' is the first step in all operations per doctrine.
- the largest autonomous force is the Amphibious Ready Group carrying a Marine Expeditionary Unit (MEU) a battalion-sized tactical formation deploying company-sized assault/landing teams and everything else is multiples of MEU (MEB/MEF) and utilizes sea-basing.
Consider what kind of payload the LHD (Type 075) and LPD (Type 071) would carry if mirroring ARG. In particular note which class and connector (LCAC or LCU) carries which asset.
Sea-basing demonstrates how civilian assets can be integrated into the operation - just imagine existing and extensive infrastructure as well as civilian engineering/logistical vessels being employed:
Considering the geography and the scale of sea construction that occurs in Asia, which is not present in North America, I fail to see the need for dedicated military vessels.
The reason why I show these graphics is because in my view Expeditionary Force 21 represents the pinnacle of amphibious doctrine, the USMC is the most experienced amphibious formation in modern history and therefore logically PLA will use USMC amphibious doctrine to inform its own and the development PLAN amphibious assets. It is "best practice" so
while graphics show USN assets we should imagine them as PLAN ships of equivalent capability to better understand the problem.
As for Taiwan the best analogy is
landing in Sicily.
I also prepared my own interpretation of "most efficient" operation in Taiwan:
Singapore is not in a position to disallow anything. If there's a conflict between China and the US and a country where the US is based tries to prevent the use of its facilities, the US will attack it. In Singapore's case I doubt things have to go that far since they operate F-35s, the US could...
www.sinodefenceforum.com
If you compare the locations and distances and keep in mind range limitation of helicopters as well as capability of modern artillery targeting logistics (see Ukraine for reference) then having a mobile airfield in support of traditional land-based staging of amphibious operations in advance positions (smaller islands around Taiwan) is critical. Sea transit is exceedingly vulnerable and amphibious operations are much more complex logistically and time-consuming than most people imagine them to be.
More land-hops won't slow down the operation and will greatly increase the survivability and tactical options. The more land-hops are available the less need for LSTs and more options for LCAC, civilian assets and air transport.
Consequently I can't imagine that PLAN would cease procurement of LHDs or choose a larger proportion of LPDs or LSTs which can be much more easily replaced by non-military assets. LHD is the only asset that can successfully
scale battle into multiple domains because of its size and
the size of air deck.
If the three-fleet (N,E & S) structure is to be maintained I would expect a minimum of 9 LHDs total (3 per fleet) and an optimal number of 12 LHDs (2 pairs per fleet) although NSF might not operate LHDs and instead SSF will have double numbers. For now the three 075s are test units. Whether more 075 follow or there's a change to another design will come from those tests. I also think that
crews are of more importance than vessels so if the "training crews" are ready then production of LHDs will commence.
I find the above to be only logical and so my personal expectations of future PLAN procurement in amphibious domain follow the above conclusions.