I am not so sure the series brings to light that much lost evidence but as usual with superb CGI, good writing and editing the programs really put it all together so the viewer gets a far better idea of the battles than simply reading it somewhere.
The one they had on Tarawa as great. I'd talked to my friend's father endlessly who was a BAR guy and the show illustrated everything he mentioned better than my imagination.
Back in the 1950s-60s all we saw was the same stock footage over and over in any movie or documentary! It was amazing that so much stuff was languishing on shelves unseen for decades and things like the History Channel have brought it to light.