you could call it an "all star game"
squads were selected based on the first 1st class team a player played for, so that would be NPC (Auckland, wellington, Canturbury et al) or Super rugby (Blues, Canes, Saders et al)
so there are some weird selections, Damien Mackenzie born and raised in southland (south island) high school in christchurch (south island)...first played for Waikato so in the North Island team
the barrett brothers are in different squads because even though they grew up together they first played for different teams
its viewed as a mix of all star spectacle and all black trial
personally, i think NZR has been a little short sited, I would have preferred high school 1st XV, then they could have done a whole lot of build up with players going back to their highschools, maybe training in their old jerseys
at the moment thee seems to be very little build up too it...its like "hey fellas....there's another game of rugby on...check it out"