KRI Tarakan is only 2400 tons with 5.500 m3 fuel capacity.
You'll need at least 4 of them to accompany a fleet to trip around the globe.
Lets we see, Supply Class from AU, its 18.000 + tons, for Oiler Tanker only, same tonnage as 2 piece of KRI Semarang.
Yes, we need huge vessel. But IMHO...