Danny's not a #3 scorer, but he gets you an efficient 12 a game. He can hit threes at >40% in a variety of ways (contested, off curls, pull up/transition, anywhere along the arc rather than having a small number of spots), which is a LOT rarer than players who are in the 38-42% range as long as they are in a relatively open catch-and-shoot situation. He knows how to drift to the open spot in transition and the half court set to get open or influence the defense, and he's a better cutter than a lot of people realize. He's not usually a volume scorer, but he did score 19 or more points 13 times this year including outings of 27 and 25.
Just as important is that he plays elite defense on ones and twos. Physically, he's 6'6 with a 6'10 wingspan and enough quickness to stay with PGs. He's also got a big bag of tricks in transition defense and scrambling to fix broken defensive plays. He's also tenacious with exceptional conditioning and effort.
Green isn't a max player, but he's worth a lot.