firstly, can i say it was nice to meet you wayne at the ukaps meet.
ok, for me i'd try to make more of an island with the stones making up the base. thats not to say what youve done is wrong BTW...its not!.ultimately, it depends on the planting scheme whether certain arrangements work. id maybe push the whole thing back a tad?...it lacks that sense of depth IMO....unless of course you plan on stuffing the back with plants. remember you dont need acres of room at the back for stems as the bulk will be at the upper 50%...if that makes sense?
also maybe adjust the height of the 3 main branches as there on a similar plane.
just remember wayne, a good planting scheme will change everything.
later matey