I played around with rivals before I left for work, and wasn't able to post until now. Any created team that you insert into the game takes on all of the rivals of that team until you move them. Then it gets crazy.
Moving oSu to the Big 12 North or anywhere else will cause WOOD to lose his rivalry with OU, but he'll get the top rival of the team he replaces. The scenario that I ran for oSu was this: Replace the real oSu with WOODs TB team. Then move oSu to the SEC West, and move Arkansas to the Big 12 South. oSu has a new rival in LSU, but loses the OU rivalry. Arkansas keeps all of their other rivalry games.
Army is a different/worse case. Army has Air Force and Navy as rivals. If you just replace Army with Olafs TB team, and keep him independent, then he will keep AF and Army as his rivals. The scenario I ran for Army is this: Replace the real Army with Olafs Army team. Move Olafs team to the Big Ten in place of Ohio State. Army's only rival in now Ohio States top rival...Michigan, of course. Ohio State is now an independent and keeps Michigan, Illinois, and Penn State as rivals.
All "real" teams, i.e. non-created teams maintain all of their current rivalries, and in some case, pick up the top rival of the team that they replaced when they moved.
Weird, but true.