Jim, I believe Hays' brigade was designated the 8th brigade very early in the war, before the Army of Northern Virginia was officially named and its divisions and corps standardized. The Confederates numbered their brigades, divisions, etc., just like the Union, but they were almost universally referred to by the commander's name. For example, James Longstreet commanded the First Corps, but it was almost always referred to as Longstreet's Corps.

I mention both Sawbuck and Stonewall Jackson in my book Lee's Tigers (p. 69). The Virginia artillerymen had taught Stonewall Jackson such tricks as sitting up at roll call and holding a pipe in his mouth. It took a few tries before what one Virginian described as "the cunning thieves" in Richard Taylor's brigade managed to steal him away. The 2nd Louisiana Brigade's Sawbuck would go into battle with the men until he was wounded in the foreleg. After that, he would straggle behind--playing "old soldier" the men claimed.

At Gettysburg, one Confederate unit (I think it was the Maryland Line but might be mistaken) charged the Yankees on Culp's Hill and their dog mascot went in with them. The Yankees killed him.