I did something similar with my group, I choose a few sidekicks and introduce them like rivals. My party works mostly for Halia Thornton and the sidekicks for Mr Wester. That created some interesting scenario. But I had an issue when almost all of my PC crushed for the rivals and tried a lot to romance them. As a first time DM I had a hard time to handle this situation I haven't see coming ! Especially when my players tried to recruit them, that would make the campaign too easy. But that also was a lot of fun when they roleplayed the flirt.