That said, I wonder why he didn't try to organize his artillery to enfilade Cemetery Hill from Ewell's rear areas just east of the town proper? It would have been closer than the Peach Orchard, and he could have done a lot of damage.
Gen. Pender was generally useless as an artillery officer, but Lee had and used E. A. Porter Alexander. But Lee (or Pender) caused Lee's batteries to be positioned all along Seminary Ridge, so that their fire tended to overshoot the Union positions and did no great damage during the big cannonade of the Third Day.
There was no officer to see the overall position and take charge, as Col. Ruggle had done at Shiloh when he cleared out the Hornet's Nest with his big, 62-gun battery.
Gregg's 2nd Calvary Division had 4,000 troopers were positioned to the rear and east of his position. He had the Union I, XI, XII Corps in his front. The Stonewall Brigade was removed from the line and to check the Calvary advance. Early sent one brigade to help the Stonewall Brigade also. This weakened Ewell...whose orders were to wait for the main attack from Longstreet. Johnson's Division was to attack Culp's Hill. Early was to follow. Rhodes was to attack west toward Cemetery Hill. These three divisions were to attack against the Union salient at Cemetery Hill.
An attack was made by Ewell on Cemetery Hill. Early's division made to to the top of Cemetery Hill but without support, they had to withdraw. General Anderson of Hill's corps was in the proper place and managed to pierce Cemetery Ridge only a couple hundred yards from the southwestern slope of Cemetery Hill. The attack had not gone off as planned...and yet, even momentarily, the Army of Northern Virginia pierced the salient. July 3rd brought another try. The II Corps did use their artillery to fire upon Cemetery Hill and Ridge.
Pender wasn't an artillery officer. He commanded a infantry brigade of brave North Carolinians. Do you mean Pendleton?
Porter Alexander was in charge of the placement of the artillery on July 3rd. But, the Federals said that the Confederates always overshot.
In his terrific book on Lee, Douglas Southall Freeman wrote that after the death of Stonewall Jackson, Lee placed Ewell and A.P. Hill in charge of the II and III Corps. What Lee did not understand, at the time, (he understood it perfectly after Gettysburg) was that Ewell and Hill never operated independently under Jackson. Jackson told them where to be, when to be there, and how long it should take. Jackson had trained Ewell and Hill never to go outside the letter of the order. No independence. Before, Lee would write to Jackson "if practicable" and Jackson would do it. He wrote "if practicable" to Ewell, and the order wasn't firm enough. Ewell had a council of war with his commanders, who all served under the exacting Jackson... This misunderstanding of the nature of his commanders would cost Lee greatly.