Good morning Grimber,
except for the cubic cluster, you displayed what I had in mind. But I would still say that the higher polycount isn't that good. That would mean to have 16 Vertices and 16 Triangles more per trunk, just for the 'X-Cluster'..
I could implement an area where the user could choose one of the three described leave-arrangements. But I need more votes for this change. At least 5.
I would still prefer, when there has to be a change with the leaves, that the leaves should rotate randomly around a trunk. This wouldn't raise the number of Vertices or Triangles. But that's also up to you.
Greetings
André W.