The attack that started on the 30th by the Union played a huge part within there own rout. But if McDowell's Corp was on the move back from the peninsula, Would the battle be that much different. For one, a smaller force makes a commander less aggressive.
...Pope attacked all day on the 29th, and publicly expressed derision for commanders who looked to their own supply lines. This is a man whose idea of warfare concorded with Lincoln's - hit the enemy as hard as you can and don't bother thinking about what they can do to you.
Without FJ Porter's force as a flank guard on the 29th - and bear in mind Pope considered Porter to be
actively treasonous for doing the flank guard job - Longstreet would have been able to attack that day.
Therefore if a commander does act aggressively due to his present information, he would still try to cover his flanks and offer as much of a reserve as practical to ensure that his army is not destroyed. And would the battle have happened?
I'm not entirely sure it's clear what my Alternate Second Bull Run concept is. The only difference here is that Pope's order on the 29th is non-discretionary; Pope genuinely was trying to attack with everything he had at once without bothering about supply lines or lines of retreat.
I believe that the powers that were in command in 1862 saw these same issues within the logistics system that would have prevented them from making such a move.
Yes, but the powers in question were corps commanders and army commanders - not Lincoln. It was at least achievable in late 1862, however, because the York and James rivers were cleared and so the main problem is getting over the Rappahanock-Rapidan in force.
McClellan could have moved on Richmond way faster, but his estimates were that the enemy was 200k.
This, on the other hand, is basically false. Not the bit about the enemy being 200K - this is correct if you use Aggregate Present, and is an overestimate of about 50,000 in AP strength - but the bit about moving on Richmond much faster coupled with it.
In April and May, McClellan's estimates are correct, so he's not moving slowly because he overestimates the enemy.
In June, McClellan's estimates are high, but the reason he's not moving has nothing to do with enemy strength and everything to do with a series of truly awful rainstorms. McClellan moves again the day
before Lee's attack sequence starts, because that's the day the ground has finally dried out enough to move artillery. (That's why Oak Grove is 25 June and the first of the Seven Days, while Lee's attack sequence opens at Mechanicsville/Beaver Dam Creek on 26 June).
The real problem in the Seven Days is Jackson coming down from the north; if there was a way to have McDowell catch him in the Valley or even just block him from escaping, Lee wouldn't have been able to force McClellan away from Richmond because the Mechanicsville position would have remained secure.