German aircraft and tanks were the best of the war. They developed the STG 44, the first assault rifle. Their problem was that while they might produce one Panther or Tiger tank, the allies cranked out 100 Shermans, T-34's, or other lesser but still deadly vehicles. God is on the side of the biggest battalions, as Uncle Joe Stalin liked to quip.
It's hard to get a sense of the individual German soldier, though. Most of the books you can get were written by German officers, and most of those were written by Generals, or by specialists like fighter pilots, U-boat commanders, or others. That's where Guy Sajer's book is so valuable. As a record of infantry combat in the German Army on World War II's Eastern Front, it's the best there is. Strangely, Sajer wasn't a "real" German by the lights of his time. His mother was German, his father French. He tried to join the Luftwaffe, washed out, and wound up as a driver in the transport corps. Later on, he volunteered for service in the elite Gross Deutschland division and that's where the story really begins.
The book has been published in a lot of different languages, and it's an old book, but it can still be found in English, at least in Paperback. I've got a thirty nine year old copy from my time in the Marine Corps, where the book was sold in the Marine Corps Association bookstore at the officers Basic School. For all I know, (and I hope it is) it's still sold there.
It's not concerned with strategy and as Sajer himself said, writing it many years after the war, he was not trying to write a history of the war. What he did want to do, and what he succeeded in doing, was recording the experiences of the individual German soldier on the Eastern Front. It's worth reading ,even if you're not a veteran. I've just finished reading it again, and every time I do I learn something new.
If you wonder what the association is with the survivalist lifestyle, read the book. You won't wonder then.