'GROPOS' is actually one of my favourites. Aside from the fun aspect of it giving a rare glimpse at ground warfare in a sci-fi setting it had some memorable, if a little clichéd guest characters (Large, Dodger, The General & the SgtMaj.) Most of all, it was a very important episode for Franklin; who some fans seam to have it in for, though I never understood why exactly. I remember hearing back during season three or four that JMS was planning on bringing Franklin senior back during the civil war and I was always curious as to why that was never followed up on.
Personally I wonder if he stayed loyal to Earthdome or defected to Sherian's side. Sure the guy may be hard headed, a bit of a gingoistic hawk but he wasn't stupid and after that ISN propoganda piece from 'Illusion Of Truth' you'd think he'd smell the BS. I mean while he may buy that Sheridan had lost it and "gone native" with the aliens, he knows his son well enough to know he's not about to start playing Dr Mengala with Lurkers.