Thomas Ricks's book The Generals did a superb job at generating discussion across the military on the merits of American generalship since World War II. My article, "American Landpower and Modern US Generalship" in the Winter-Spring 2013 edition of Parameters, was my attempt to add depth to the dialogue about the major generals who led division-sized formations in Iraq and Afghanistan since 9/11.
To be sure, the article is not all encompassing. Although the post-9/11 group of major generals is a small data set, it is almost one-third the size of the World War II cohort and will continue to grow while the U.S. military assists the Afghan government's counterinsurgency operations for the next several years. Strictly speaking, it might not be significant by the mathematical definition, but the division commanders of Iraq and Afghanistan are a notable group in the historical sense. While I concede the mathematical limitations of the evidence presented in the article, there is enough hard evidence to allow us to move beyond questions of correlation and to discuss the matter of causation, which, in the end, is far more important.
I acknowledge Mr. Ricks's questioning whether military organizations should place a premium on reducing disruption. In forming my thoughts on the adverse outcomes of firings, intellectually I drew upon literature studying similar experiences in business and professional sports. During a year as a battalion commander in Afghanistan, I (and I'm sure my higher headquarters) wrestled with how to improve the performance of subordinate units in an extremely ambiguous environment. Reliefs rarely seemed the best way forward for my unit or our counterinsurgency campaign. There is a finer line to be drawn on this measure than Ricks concedes.
Thanks again for the opportunity to contribute to the discussion. I hope others are able to expand on and contribute to the conversation.