I recall that I first learned about the Peter Principle at the same time that I was reading Lee's Lieutenants by Douglas Southall Freeman, and there was a weird

I recall that I first learned about the Peter Principle at the same time that I was reading Lee's Lieutenants by Douglas Southall Freeman, and there was a weird synergy between the two. As the war continued, attrition took its toll on the Army of Northern Virginia's officer corps, notably after Jackson's death at Chancelorsville. The two generals that replaced him, Ewell and A.P. Hill, were very good divisional commanders, but poor corps commanders. That tome is littered with other examples of officers excelling at one level of command, but being ill-equipped to perform at the next level.