It is aired in NatGeo Channel Asia too.
Generals at War, IMO is a pretty good documentary for starters. I watched the El-Alamein, where they pitted Monty against Rommel and the Kursk, von Manstein vs. Zhukov.
Overall, it is very generalising, but in some aspects it is quite detailed. Like in El-Al episode particularly, I learned that German blood transfusion method is pretty outdated (sucking and delivering the blood from the donor to recipient using needle injections), while the British employed the current method of having cooled blood bags.