So with what I've read about Gettysburg specifically, which includes Pfanz, Sears, and Bowden. The picture I get around dusk on July 2nd is the following:
At the breakdown of the echelon attack on the Confederate Side from south to North to east:
3rd Corps: ANDERSON - Posey (1300 Men), Mahone (1500), PENDER - Thomas (1300) supported by Scales (?? probably 1,000) Lane (1500) supported by Perrin (1300) TOTAL: 7,900 Men
2nd Corps: RODES - Daniel (1,300) Ramseur (750), O'Neal (900) Doles (1,100) EARLY - Hays (1100), Avery (1,000) JOHNSON - Jones (1,520), Williams (1,105), Steuart (2,120) TOTAL: 9,795
For the North from south to north to east:
Northern Cemetery Ridge and Cemetery Hill
II Corps: Smyth (1,000), Carrol (918), XI Corps: Smith (1,422) Von Amsburg (828), Krzyzanowski (731), Harris (525) Von Gilsa (710)
TOTAL: 6,134
Culp's Hill
I Corps - Iron Brigade (616), Cutler (938), XII Corps - Greene (1,060), Webb (268)
TOTAL: 2,882
7:00 - Posey should have been hitting smith
- Mahone should be moving into support Posey's left flank
- Johnson's 3 brigades begin attack on Culp's Hill
7:15 - Mahone should be hitting Carroll on north cemetery ridge (1500 vs. 918)
7:20-7:30 - Pender's full division would have went in and it's full weight would have went up against Smith's brigade and possible swung something south to support Mahone. (Pender's 5,000 vs. 1,422 + Federal Artillery)
7:40 - Hays and Avery begin attack, which collapses Von Gilsa and Harris's lines. (Early's 2,200 vs. 1,235).
What's interesting about all of this is what actually happened. Von Amsburg rushed to Culp's Hill and arrived around 8:20 to support Greene against Johnson. That probably wouldn't have been possible if Pender and Early are both attacking Cemetery Hill at same time. Carroll and Coster come up to support Von Gilsa and Harris's collapsed line and save the situation, but Carroll and possibly Coster wouldn't have been able to do that if Carroll is having to deal with Mahone, in fact Coster probably gets sent to help with either Mahone or Pender's attack.
One last piece I didn't mention is that Rodes moves into position but never attacks if he sees Pender attacking Cemetery Hill in his front and sends his 4 brigades in I don't see how the combination of Pender, Rodes and Early don't shatter what is up there, and Meade has nothing to reinforce it with as everything else is at the southern end of the battle. Another factor is that Rodes was poorly positioned to begin with. Ewell should have moved all or most of the command to the East side of the town. In that situation Rodes would have been able to support both Early and Johnson easier.
Thank you so much for those numbers Tom very insightful.