4. The Outsiders
Batman is no stranger to royally pissing off the Justice League. Its happened several times, and hes quit or been kicked out more than once. Justice League: Tower of Babel showed that, in true Dark Knight fashion, Batman has a contingency plan for any member of the League going rogue and having to be taken care of. Long before that though there were The Outsiders, a group formed by the Caped Crusader after his expulsion from the Justice League. Neither sounds all that different from whats going on in Injustice so it stands within reason that Batman would get the band back together. Obviously, as its a team and not just an individual there is a lot of flexibility with which members to include from the various iterations of the team (Tim Drake, anyone?). The Outsiders have varied from various vigilantes, to a team of humans with special abilities resembling the X-Men, to most recently recruits of Batman, Inc. At one point the reigns of this band of rogues were given to Nightwing, so their loyalties within the game could be split and fractured.