This isn’t unique to the Green Party, pretty much all the major parties have internal divisions. Take the recent Labour stuff where the socialists have butted heads with technocratic front bench over the two child benefit cap. The Greens are different in that they don’t whip their MPs or Cllrs, as they believe they should be free to vote with their conscience, which has the major disadvantage of making the party line muddy and hard to count on.
I haven’t got to this yet, but all I want to know is if the toff in my head ever shags the stable girl.