Yes. I found a quick and dirty way to do this which I posted earlier:
http://forums.taleworlds.com/index.php/topic,194342.0.html
Lately I've been experimenting with changing faction relationships and party sizes so there are more battles going on and more opportunities to gain or lose rep with various factions -- a much better long, term solution. For example, I made Confederates enemies with all outlaws, the Union Army, Indian Raiders, and every other faction that seemed remotely likely to be hostile to them. Then I made the Confederate party sizes more variable, so sometimes you only get a handful and sometimes you get a lot. That way you're more likely to find smaller groups of them being attacked and larger groups attacking. So far the results are promising.