I don't get this #1,#2 thing as if it was set in stone. Green is a scorer, and like Galeto said, he lacks moves and he should be working like a mad man next offseason, to improve his footwork and ballhandling, because he's a good finisher. He's a decent shooter, and I'm still waiting for him to make another step on D. Remember he's feeling like 90% recovered, so more confidence will be good for him.
And basketball is a team game, you need balance at any time, and then you need talent. Obviously if you have a superstar who is helped by the refs (Jordan, Shaq, LeBron...) it's easier, but you still need balance.
This team needs a rim protector/post defender C (Melo? or FA), a skilled PF who can score inside/outside and rebound (KG is that, Sully if healthy could really be a Love type of PF), a SF who can do it all (Pierce is that, Green could be in his own way), an outside scorer at the SG (Bradley??) and a PG (Rondo is a star). If you have enough talent at every spot, and backups who are good enough to fill in for the starting five, you are good to go against anyone.
Of course, the biggest question is at C and SG (and PG if Rondo was traded). This team has good prospects at SF and PF for when KG/PP retire, but Avery is not a Dumars type (yet), and Melo is years away from filling that role. In an ideal world, Rondo stops being Mr Hide/Dr. National TV and he can be consistent. Sully has the talent to score inside and outside, and Green can give you 20 on any night. If Avery keeps improving his offense, you have 4 players who can score consistently, and then you need that physical C who can cover for lack of rebounding, defensive lapses, and who can put alley-oops and put backs. The problem is we're missing him since forever. Perk was a decent option, but if you want to win it all without 3 Hall of Famers, you need a better Perk.
I hope we haven't seen the best from Jeff Green yet, but we need a balanced team.