There was a faint implication that it would be more like "Grant the Butcher charges Johnston",though probably more through bad assumptions on the part of the reader.
Who's Alfred von Manstein? I assume you meant Erich von Manstein and if you did nobody here is trying to say he was an Erich von Manstein. All I've said about Johnston was that good officer who could have done better and that Seven Pines/Fair Oaks was the event that decided his evolution as a General. Just cause you dont like him and I do doesn't mean I'm trying to say he was the greatest general in history.
And what do you mean about communicating the truth later. Surely later Davis must have realized Johnston was only bluffing. Why would Johnston need to explain it after he'd pulled back and his bluff had been exposed?
I think the problem here - and this is my understanding of the mess - is that Davis felt that Johnston could have done more and didn't. And Johnston's failure to communicate properly meant that instead of coming off as leaving an untenable position after having outfoxed the enemy, he came off as leaving a defensible position and Johnston never presented something to make Davis see otherwise.
Assuming for discussion's sake Davis is thinking rationally but narrow-mindedly. And that Johnston is showing a lack of insight into what Davis thinks rather than a lack of ability or willingness to fight.
The accuracy of the latter is unresolvable, but its safe to say that the man who launched Seven Pines/Fair Oakes at least had nontheoretical situations where he would go on the offense.
Could Johnston havd communicated better? Of course he could but so too could Davis have tried harder to assertain the truth. He certainly didn't go out of his way to meet Johnston or visit the front after 1st Manassas or ask him to provide details of his command or position. So they both could have done better.
Johnston, as part of doing his job, is obligated to keep Davis informed of his needs. Davis, as president, is not obligated to inspect each and every individual military formation. I'm not saying Davis is free from blame here - the two seem to be peculiarly suited for conflict in situations like this due to their stubborn defense of their position and their views without either ever trying to see what the other guy is seeing. That inevitably makes sorting out who did the wrong difficult because the will to cooperate is conspicuous by its absence.
But in this particular case, the responsibility really is with the army commander to make sure the president is fully informed. Davis shouldn't have to do anything extraordinary to ascertain the truth besides read Johnston's reports to him and compare them to the reports of the other relevant people (Northrup, for instance) to see how things are working - or not working as the case might be.
That's not to say Johnston should be doing anything extraordinary either - just giving full and complete reports on a timely basis.