Marshalls book is highly controversial when it was published and has been cited by many respected historians. It wasnt until Dr. Roger Spiller did a study on Marshalls claims did anyone realize there was a problem.
Here is a link with a brief of Dr. Spillers results. I personally dont know who is right but I do know Marshalls book is not accepted by some military historians and sociologist.
According to one source I read even John Keegan has used Marshalls books and quoted from them and Keegan is without a doubt one of the best living military historians.
I disaggree with the article calling them "gullible". If a respected member of the military with a track record such as Marshalls writes a book that puts forth a new theory and it seems to be well researched and documented; I dont blame them for giving him the benefit of the doubt. If the critism is true, they were not gullible, they just didnt check his statements enough.
I was reading through the sites linked from that link.
The only slight problem I have with all of this is that they only seemed to start going after his results in 88, after he had died.
He may have been a sloppy researcher (Marshall) but to use some of the terms they do when the guy isn't around to defend his work strikes me a bit low. Thats the only thing i find slightly tasteful and distracts a bit from what Spiller is saying. Whether that is Spiller saying it or not or someone hyping his work using that language is another matter.
I honestly haven't got any clue who is right and reading thru all the material to get a better idea is something that will have to wait for another day. But it's an interesting point that i will have to check out.