Well, I did say that most of Nusantara's warships by 2014 were foreign made such as the their VTOL carrier, KD Perajurit was formerly the Indian Navy's INS Vikrant and their LPH, KDN Megah was of the US Navy's old Iwo Jima class, USS Tripoli. Her destroyers coming both the US and German Navy (Spruance class and Lutjen class)
wait, what?
I see some logistical problems coming along even now.
indonesia had the van speijk class bought from the netherlands in service. seeing the age of your other vessels, they would still be in use. so, you'd look at the dutch and british for spares. they also had italian guns.
the INS vikrant, british
iwo jima = US, steam powered
spruance = US, gas turbine powered
lutjens class, US and germany, steam powered
even in the propulsion systems alone, 5 classes of ships (at least, because the other nations would have had ships in use too when this AU story takes over) already use 4 or 5 different logistical chains, all requiring storage, transport, and the politics of getting them.
as, by 2014, real life indonesia and singapore at least have ships specially designed for them and new build, I see no reason why not go for new build ships. they are more capable, and, especially looking at the above, most likely cheaper to maintain then all these second-hand vessels.
in addition, the fleet buildup seems a bit unlikely, not fitting the role my mind says they should have in your navy. but I will not comment on that further, although I will answer questions you might have about that.
so yeah, just put a little bit more thought into this