The North had it's share of fratricidal politics and detrimental infighting. Take Grant's career:
- Halleck perceived him as a threat and tried to put him on the shelf, at least until Halleck was called to Washington.
- Grant was also saddled with the politicking, self-seeking McClernand until the middle the seige of Vicksburg.
- One of the reasons Grant had to travel with the Army of the Potomac was in case it formed a junction with the Army of the James. If that happened, the incompetent political general Butler ranked Meade, and would have insisted on taking over.
- Grant resented George Thomas, likely blaming him in part for Halleck shelving him after Shiloh. They never really got along, and Grant almost sacked Thomas before the Battle of Nashville.
Yet the South had more partisanship in its government for sure. As a Southerner, I think it's a rare Southern politician who is good at anything other than slinging mud, obstructionism, and (political) bomb-throwing. You can see a lot of that in the Confederate Congress. The upper class of the South was also full of would-be aristocrats, and for every Robert E. Lee in that bunch, there were three or four Rhetts and Polks.
I like what Robert E. Lee said about Congress:
I have been up to see the Congress and they do not seem to be able to do anything except to eat peanuts and chew tobacco.
In an example relevant to the book's scenario, at the end of the story Hooker's XX Corps is transferred to the AotT. That forces Sherman to stay with the army, lest Hooker cause problems for McPherson, because Hooker is an ambitious schemer backed by the Radical Republicans and he ranks McPherson. It's a spin on what actually happened: when McPherson was killed, Hooker resigned in a huff when he was passed over for command of the AotT, and it was instead given to O.O. Howard, the hapless former XI Corps commander who used to work for him.
As an aside, why is it that the CSA's leaders (both military and political) always seemed to be bickering with each other? Was it something inherent in Southern culture, or something else entirely?
Whatever the reason for that infighting, I think that was the biggest reason, or one of the biggest reasons, for the downfall of the Confederacy.