Scraping the Barrel: The Military Use of Substandard Manpower, 1860-1960 is a collection of chapters by several authors covering how armies employed "substandard" personnel during the era of mass conscription. These include chapters by fairly well-known historians such as David Glantz and Dennis Showalter. There was a fair amount of interest in this book when I posted an external review of it a few years ago, and I was pleased (and more than a little surprised!) to recently see a copy in a local remainder bookstore.
This is a fascinating book, though it's let down by its title. It really covers how armies used manpower they considered to be substandard, for reasons such as racism in the case of African-Americans, rather than only personnel who weren't fully up to the job. The book's main theme is that these personnel typically gave useful service, as long as the tasks they were assigned matched their capabilities. This is well illustrated by Glantz's chapter on the fairly ruthless but successful use of manpower by the Red Army in World War II and Peter Simkins' chapter on the failure of the British 35th Division of World War I, which was initially manned by soldiers who were well below the Army's minimum height. As is usually the case with edited collections, some chapters are much better than others and the coverage of topics is uneven (I don't think the book needed two chapters on Waffen-SS recruitment of ethnic Germans, for instance) but all of the chapters are interesting and well executed. Editor Sanders Marble wraps things up well in a conclusion arguing that the emphasis on elite units by historians has led to the history of the vast numbers of "substandard" personnel who served in conscript armies being almost ignored: this may be a gap Wikipedia can contribute to filling.
All up, this is a very useful work, and nowhere near as eccentric as its title suggests!
Publishing details: Marble, Sanders, ed. (2012). Scraping the Barrel: The Military Use of Substandard Manpower, 1860-1960. New York City: Fordham University Press. ISBN9780823239788.
Recent external reviews
US Army soldiers in South Vietnam during 1968
Baker, Gary P.; Lambert, Craig; Simpkin, David, eds. (2018). Military Communities in Late Medieval England: Essays in Honour of Andrew Ayton. Woodbridge: Boydell Press. ISBN9781783272983.