Thanks for that interesting video.
However, I'm not convinced that Mr Smith was accurate when he described confusing orders from General Lee (starts at about 7:40) ordering Ewell to march to
"either Gettysburg or Cashtown as circumstances dictate". That didn't sound right to me. I looked it up and found Lee's order here (starts near bottom of page -
https://babel.hathitrust.org/cgi/pt?id=coo.31924077700262&seq=945&q1=). What Lee actually says to Ewell is:
I desire you to move in the direction of Gettysburg, via Heidlersburg, where you will have turnpike most of the way, and you can thus join your other divisions to Early’s, which is east of the mountains"; and
"When you come to Heidlersburg, you can either move directly on Gettysburg or turn down to Cashtown."That is clear to me. Lee wanted Ewell at Gettysburg but he was to first concentrate his Corps at Heidlersburg.
Importantly, he did not want Ewell's Corps arriving bit by bit. Hence to need for Ewell to join with his other divisions at Heidlersburg which then provided the option of moving to Cashtown or moving
"directly on Gettysburg". Lee also said
"But if the roads which your troops take are good, they had better follow you." The roads were mostly good as Tim Smith states that when they marched out of Carlisle they moved 17 miles that day. That tells me the roads were good as 17 miles is a fair day's march in what I understand were hot and humid conditions.
Also, later on Mr Smith queries that Ewell had divisions marching along
"two parallel routes heading in the same direction" (there is a lengthy pause, and weird emoticons pop up in the video implying that this was an incomprehensible thing). Marching along different roads to arrive at a designated destination is the preferred method of march as the entire force gets to their destination quicker and in better order. It is far less advisable to have the entire force marching along one road as the force arrives later because when it is in 'road column' the force is stretched out (10,000 men will occupy about a mile of road, then there are the artillery trains and supply).
Mr Smith blames General Lee for Johnson not arriving at Gettysburg with the other Divisions of Ewell's Corps. I can find nothing from Lee to Johnson. Johnson was, in Lee's mind, Ewell's responsibility (
"thus join your other divisions to Early’s"). Ewell has to answer for this,
not Lee. Ewell has some questions to answer in regard to 1 July too, but that's another story.