Do not worry .. You are not alone in not understanding it. All those Generals and experts also do not understand it.
First thing = In mountains Vallies and passes are the only avenues of movement across mountain ranges hence most important.
See the Maps and the blue lines.
Galwan River provides an ingress into Aksaichin one side and into Shyok River vally on the other. The valley leads us directly to Northern portion of Aksaichin near Chinese raod G-219 . The Chinese have constructed a raod into that valley. The immidiate northern brach near Shyok takes us directly behind all Chinese posts in Gogra, PP17. PP19, Depsand and DBO.
Therefore it is the most vital valley in enire Aksaichin. Anyone who has control of this valley can come into Shyok valley from Aksaichin or Vice versa. It is the spine of Chinese control of Aksaichin.
View attachment 50845