What sources/texts provide a rich understanding of comparative military strategies of the North and South?
I'm not sure entirely what you're looking for, but Shelby Foote's The Civil War: A Narrative is a pretty engaging narrative of the military history of the war.
Foote doesn't footnote though, so if you're looking to find the sources he's referring to, it can be a bit of a pain.
For a beginning study, Bruce Catton's trilogy is very excellent because he is good at providing dates, numbers and a good overall description of all the major campaigns. The third volume is titled: Never Call Retreat. I think the first one is "The Coming Fury." You can look it up.
In the eastern theatre, D S Freeman Lee's Lieutenants is very good from southern side. Cattons' trilogy of the Army of the Potomac is very good overview of the northern army, Army of the Potomac.
The western theatre doesnt really have a good overall single treatment. Wiley Sword was the go to book on Shiloh, but I think there is a new one. Clifford Downdey had one on Chickamauga, but there is a new one.
In order to compare military strategies I'd suggest the following:
try works by Prof Gary Gallagher, particularly the one on Lee's High Command, you can also find some of his lectures in youtube
Glathaar "General Lee's Army: From Victory to Collapse" is quite good in terms of army organization
I always found memoirs very useful, Longstreet's "From Manassas to Appomattox" is very good and Grant's memoirs too.
and yes, I always loved Shelby Foote's "The civil war a narrative" essential to see the ACW as a whole.