I don't think us (Ipswich) need anymore rivals, the only ones that I could think of would be Norwich and Colchester for obvious reason, and maybe West Ham and Sheffield United, and that's pretty much it.
In my opinion what would be the point of creating new rivalries with other teams already on your team info page, 3 or 4 and I'm fine with that.
Managers on the other hand, if someone like Alan Pardew were to try and buy all my best players, or always slate me and my team before and after a game, then I would like an option to include them on my rival managers on my manager profile, we have favourite clubs, why can we not include rival clubs?
Or how about we could have an option to add our favourite or players that we hate, so if I were Ipswich manager then I could have the option to include Pablo Counago on my favourite personnel list just like they are able to add me.
Then I could also have an option to add someone like Darren Huckerby to my dislike list, because well, I hate the bastard.
Feels like a suggestion.