As for karr.. I don't think all of their kids are from the westbank
Karr and Walker are both Charter schools under the Algiers Charter School Association. They can pull kids from all over Orleans Parish, they don't have to be just in Algiers.
Landry was being run by either a different Charter group, or the state. I don't think they are being merged with OP Walker.
And also, if you did merge Karr and OP Walker, it wouldn't = 4A Dynasty. It would equal a team that could probably win the Southland conference.