Bruce is also a considerable Civil War buff, and may have influenced JMS's choice of name and ancestry for his character. He badly wanted a role in Gettysburg and teased one of the TNT reps assigned to B5 that he wouldn't work for her because the network wouldn't let him audition for the earlier film, which she had worked on.
(I still think he would have made a better Robert E. Lee than Martin Sheen, especially after watching "SiL".)
Bruce, at 6' 3" would have been a little tall to play Lee, who was a bit under six feet, but better than Sheen at 5' 7". Bruce could never have played John Sheridan's ancestor, who was famously known as "Little Phil". (Lincoln once wrote General Sheridan a letter in which he said, "... Before the war I was of the opinion that a cavalry officer had to be at least six feet four inches tall. But five feet four will do in a pinch.")
Phil Sheridan won't be in Gods and Generals as far as I can tell from the IMDB cast list. Not surprising since the book, at least, deals mostly with the men who would later play critical roles at Gettysburg, in the years before that battle, and Sheridan wasn't one of them. Like Grant, Sheridan served in the west during the early years of the war. (A surprising number of people assume that Lee and Grant faced each other at Gettysburg. In fact, Grant was a subordinate General operating in Tennessee at the time, and would not be made commander of all Union forces until after that battle. George Gordon Meade commanded the Union forces at Gettysburg. Lee himself was only commander of the Army of Northern Viriginia then, and had no authority over other Southern forces.)
In 1863 Sheridan was fighting around Chattanooga in Tennessee, far from the scene of the action in Pennsylvania, while Grant was beseiging Vicksburg, TN on the Mississippi river. (Vicksburg surrendered, giving the North control of the river, on July 4, 1863, the same day Lee's army retreated from Gettysburg. The twin Union victories marked the beginning of the end of the Southern cause.)
Regards,
Joe