2. Mavericks have lots of flexibility with Green's contract
One of the more sought-after commodities in the modern NBA is role players on good mid-level salary deals. NBA talking heads have operated under the notion that the "middle class" is suffering in the league right now, and they aren't wrong. According to Kristian Whitfield of the New York Daily News, NBA teams are allocating about two-thirds of their salary to their top three players on average.
Josh Green probably isn't the third-best player on most NBA rosters, but he has more than enough potential to turn into that for Dallas this season if he plays as well as some of his Australian National Team teammates have said he can this season after he impressed during FIBA World Cup Play for Australia.
Nonetheless, the Mavericks put themselves in an extremely favorable scenario with Green's contract because of the $13.67 million average per season (Not an exact figure for every year of Green's deal).
Green's contract should be easy to mix and match with different trades because of how valuable good role players on fair market value deals are in today's game.
Idealistically, Green ends up working out in Dallas to a premium, forcing the Mavericks' hand to extend him to another contract once he's 26 years old as he's entering his eighth season in the league. If this takes place, then that will be a sign that Green severely outplayed his new contract extension.
Whatever happens though, the Mavericks have put themselves in a position to not lose value on this deal given how much promise Green showed last season. If he somehow peaked in production last season, then Dallas still doesn't necessarily have a negative asset on their hands. While they are rightfully invested in Green in the immediate future, they won't have to worry about losing value on a potential Josh Green trade down the line, barring something absurd like a career-altering injury to Green.
Dallas has put themselves in a great position with the way they handled Green's extension as far as future implications go, but our next reason on the list shows why they could've just made one of the better bargain deals in the NBA.