Some random thoughts:
1. I think Green can definitely be a starting SF forward on a championship team
2. I also think he can average 20 and 8 with starter's minutes - and that he will mix in some monster games along the way.
3. But I see him more as a Cornbread or Worthy level player and not a Magic Johnson, Kareem, Bird, Pierce, Rondo, KG type player. Meaning, I'm not yet convinced he can be your "go to guy" on a consistent, night in night out basis. He will carry you some nights - but like others have said, I don't know if he has that "go to guy" mentality. He may develop it as Pierce moves out of the way in the next few seasons, we'll see - time will tell.
4. Right now I project him as our future starting small forward and a 3rd or 4th option on that team.
Rondo will be one of our go to guys on that team. Depending on how Sully develops he could be another go to guy in the post.
If Sully becomes a beast in the post, I would say we will still need one more "go to guy" to go with Sully and Rondo if we want to win rings - maybe an off guard.
Then, players like Melo if he pans out, Green, Lee, Bass, etc...fill in as excellent role players.