Greene is a solid player, he's just out of position. Once Branch is up to speed, it wouldn't be a bad idea to keep a three guard lineup out there with him, Harrison, and Greene.
I feel bad for Phil because everybody is jumping on him. The fact is he's playing his heart out, he just doesn't have the handle to be a starting PG at this level. Needs to play the SG/SF spot and spell Harrison when he needs rest.