I am not very well educated on the specific accomplishments of the generals but my own opinions are similar to the others above. I believe Jackson and Lee were exceptional but even that is difficult to prove. The Southern Generals were fighting on their ground and had assistance from the population the Union troops and leaders didn’t enjoy. Also, for most of the war, Lee didn’t face a first rate tactician, so he may appear better than his true capability. Jackson did run wild against union forces, but his knowledge of the terrain may have been more of an advantage than most can quantify. Jackson taught at VMI so he was certainly very well acquainted with the geography of the Valley.
The Union generals have no qualities to recommend them. The few that achieved success were either facing little to no genuine resistance or had such resources that even when squandered would produce some positive results. Sherman would be a war criminal even only 80 years later, and much more by todays standards. Grant would have been reviled for his unnecessary losses. He could not have been elected president on his war record with the media we have today. Burnside, McClellen and others had some good qualities but there were no top ranking Union tacticians I can note.
It is unfortunate that Lee’s men didn’t take the ridge at the first opportunity (Gettysburg) for the purpose of giving him a better rating as a field general. On the other hand, I know only few that truely wish the Soulh had successfully succeeed from the Union. If the South had a significant victory at G-burg, all history may have changed significantly.