It also seems to me to settle the question as to whether there was a surprise.
I do not question the personal courage of General Johnston, or his ability.

But he did not win the distinction predicted for him by many of his friends.

He did prove that as a general he was over-estimated.
General Beauregard was next in rank to Johnston and succeeded to the command, which he retained to the close of the battle and during the subsequent retreat on Corinth, as well as in the siege of that place.
His tactics have been severely criticised by Confederate writers, but I do not believe his fallen chief could have done any better under the circumstances.

Some of these critics claim that Shiloh was won when Johnston fell, and that if he had not fallen the army under me would have been annihilated or captured.

IFS defeated the Confederates at Shiloh.