IMHO
Some historians think that A. S. Johnston was the more grievous loss, who was killed at Shiloh. He was the shining star in a Western campaign that, on the Confederate side, was blotched with poorer leadership than was available in the East. Poor, uncooperative, or incompetent generals like Braxton Bragg and Leonidas Polk abounded, and the more energetic generals tended to get shot by sharp-eyed Western farmers in blue uniforms, as at Pea Ridge and Shiloh. Someone pointed out the mismatch between the average Southern soldier in the East in 1862, and the shop clerks and sutlers who were poured into blue uniforms and sent south to soldier for Irvin McDowell and George McClellan. Well, it wasn't quite the other way around in the West (U.S. Grant shook several bullets out of his own uniform after the first afternoon of Shiloh), but as things turned out, the Southern leadership talent was killed in the early going, leaving Grant, Rosecrans, and Sherman a relatively easy time of it.