After taking a look at OneAlex's mix, I did see that there was indeed... "GWX - Indian Ocean Campaign Files Only", think it is labeled that same way... BUT... can neither confirm, nor refute this... since I don't have stock GWX set up currently... to know for certain.
That said... would imagine that, that similar mod pack, would in all likelihood... would need to be activated... BUT, what steps to take in the proper order... am not sure of, as with My careers, I've kept them to being stationed in the Atlantic, only.
Will observe the answer/s back on this... as I have thought of attempting to do a career, where a Kaleun gets assigned to operate out in the Pacific area of the war.
On this, am going to back out & let more... experienced hands, prevail... here.
All the best, in getting this further sorted out, for you to a safe & happy conclusion.
M. M.