Smart should be compared to players like Raja Bell. Not guys like Draymond Green. Smart is nowhere near guys like Draymond.
Raja Bell at his peak was a top 10 SG (as is Smart today) because of how well rounded and efficient his game was. Like Smart, Bell was an elite defensive SG (first team All Defense) who had good defensive versatility (PG, SG, SF for Bell). Bell was a superior shooter to Smart at 40+% from three point range and also finished among the league leaders in both attempts and makes.
Bell, like Smart, was also an above average ball-handler and passer for a shooting guard. Larry Brown was intent on training Bell to become a PG for the 76ers to help provide defensive balance alongside Allen Iverson. He had the ball-handling, decision making and passing necessary to initiate the offense and could then move into a more secondary role allowing Iverson to take-over while also giving Philly legit size defensively to matchup against opposing SGs giving a break to the smaller Eric Snow. Smart offers some better playmaking and driving ability relative to Bell to offset some of Bell's offensive advantages as an outside shooter.
As a rebounder, Bell while fundamentally solid was behind the likes of Marcus Smart. Not as able in matching up / boxing out bigger body players and competing for rebounds in traffic.
Now to Draymond Green ...
Draymond Green was the best defensive PF in the league for several years running. Winning the DPoY once. He was the best defender on multiple title winning teams. He was the main rebounder leading rebounder on multiple title winning teams. Several times leading all players in total rebounds in the playoffs. During this stretch, Draymond Green was also the best or 2nd best (Blake Griffin?) ball-handling PF in the league. And the best passing / playmaking PF in the league.
In addition to this, Draymond Green had the defensive versatility to be able to matchup against centers. Against much taller and often stronger players. Allowing Golden State to put a lineup on the floor that was nearly impossible to stop from scoring the ball. 5 offensive threats who can all dribble, pass and shoot. Stretching out the floor and making it impossible for opponents to double up on Steph Curry & Klay Thompson without leaving someone wide open in acres of space to attack and make a play. This defensive versatility gave Golden State a huge advantage over opponents.
Just take a moment and look at how huge those non-scoring contributions are:
(1) DPoY level defense
(2) leading rebounder on title winning teams & for playoffs
(3) 1st or 2nd on team in assists as a PF and often finished top five in total assists in the playoffs as a PF
(4) Lineup versatility due to defensive versatility that allowed his team to create huge advantages over opposing teams in terms of offensive flexibility while maintaining defensive integrity.
Those non-scoring contributions are absolutely massive.
They far outweigh anything Smart or Raja Bell are able to bring to the table. They give nowhere near the rebounding contributions. They give nowhere near the playmaking (especially relative to position / opponent) contributions. Both are standout defenders but neither were / are a defensive anchor. Nor do they create the type of lineup flexibility that gives their team a monumental advantage over opponents.