As I understand it, this is an essentially unique capability (at this time ITL.) What are the barriers preventing the other great powers from developing a similar capability? (Now, I know that you can't just snap your fingers and have the capability overnight, but you know what I mean.)Yes right now ((as of 1910) the Empire could launch a successful opposed amphibious assault on say Formosa from Hong Kong with say two or three divisions as long as the opposition wasn't too heavy. But more important, they could keep them supplied without taking a reasonably significant port. That is their advantage, coordination and logistics.
(We're presupposing that other Great Powers would genuinely benefit from having the capability, which isn't a given.
* Political/Civil? (Government/Establishment doesn't see a need, or wants to keep the military from having the capability for whatever reason.)
* Doctrinal/Conceptual? (Military Establishment doesn't see the need, or maybe even can't even fathom that it's something that's possible.)
* Interservice squabbling? (The Navy won't stand for it unless they control the landing forces, and the army won't stand for it unless they control the boats etc.)
* Technical? (Relevant Defence Industrial Base doesn't have the capability/spare capacity to produce the necessary kit.)
* Lastly and probably most importantly, Financial? (AKA: They have a use for the capability, can see the Doctrinal use, can produce or procure the relevant kit, but just don't want to have to pay for it.)