My point regarding Heintzelman still stands. Heintzelman’s hand in battle was largely invisible but uninspired throughout the Peninsula Campaign. It always seemed like his subordinates were making the decisions, not him.
Erasmus Keyes was a Republican with abolishment sentiments, but completely lacking in proven talent. His tenure as brigade commander at Bull Run was unimpressive and his name is almost completely absent from the diaries of his men, suggesting that his leadership was also uninspired. As corps commander, he had few opportunities to show any brilliance. The biggest display of any talent he had was Seven Pines: he displayed incredible bravery in encouraging his troops but acted poorly as an actual corps commander. Reading the Official Report there are only a few instances mentioned of him interacting with his brigade and division commanders. In summary, he did not seem to have interacted with Casey's division command at all, only referring to the reports of Casey and his brigade commanders and stating he had many opportunities to observe their activities. Instead he was personally directing individual regiments and batteries in the action, positioning and repositioning them. He had lowered himself to the position of brigade command at best, focusing on the trees but not the forest. Not effective command and control at all.