How did Maxwell do this?
19th century Americans did go on as Jackson and the other characters do and did get overly sentimental, but it doesn't go over well with 21st century audiences. I don't object to the sentimental use of the servant, the child and the wife to humanize Jackson, but it didn't have to applied so thickly.
Maxwell and Lang did try to give us different sides of Jackson's character, though one can certainly argue about the balance. Some have alleged that the scenes of Jackson and his servant attributed views to the General that he didn't express in the historical record. But the film also showed something of the cruel or callous side of Jackson as well as the tender-hearted side he showed to his "esposita."
Sometimes, "less is more." A good director would have been able to make less talk mean more to the audience. If you are a die-hard fan of Stonewall, you probably took it all in gratefully, but the static, tableau-like quality of the film undercut its virtue of historical accuracy even for some viewers who would be receptive to historical dramas or epics.
Tolstoy understood that he couldn't make Napoleon or the Tsar or General Kutuzov the hero of "War and Peace." And Margaret Mitchell knew better than to take Johnston or Hood as her protagonist. Characters from actual history, generals and statesmen, tend to make fictions into static pageants or chronicles. Fictional characters give the author an opportunity to explore and move around against the backdrop of history. They can be more alive than the great heroes of history, and following them can be more of an adventure and less of a lesson. In Tolstoy and Mitchell you get to see both the official rhetoric and the underside of the war. "official story."
Actual historical figures are too nailed down by facts and sources and the rhetoric of their day makes them inaccessible to contemporary viewers. So one either distorts them to make them modern figures or leaves them as they were and very alien to modern ways of looking at the world. In both "War and Peace" and "Gone with the Wind" the main characters are links between their own day and present-day mentalities, and it works well.
Shaara and Maxwell showed daring in choosing to focus on the generals, but I don't think all of Maxwell's choices paid off. Maybe he'd have benefited from "bridge" characters who unite our own ways of thinking with those of his characters (as Pierre and Natasha, or Rhett and Scarlett do) rather than plunging 21st century viewers into the speeches and sentiments of 19th century military leaders.
It's good to have a lot of the war recreated on film and Maxwell's ambition is admirable, but I don't think "Gods and Generals" works well as a movie. I think maybe Maxwell misjudged his medium. I haven't read the novel, but it might have worked better as a miniseries with each episode focused around a different battle.