Well....Melo isn't nearly as useless on defense as people make him seem.
So it's not like he'd be a total liability out there. In fact I wouldn't even rate Melo's D at below average, he just has higher expectations as a superstar player to perform at that level on both ends, which he doesn't always do.
That said, how bad could a player with 20 JS and decent rebounding be?
you are right, but when you say melo type of player the people understand it, Artest had also a nearly MVP like season with 20+ points per game so he isn't also such a pure defender - but when you say it you understand it like that.
Maybe i could have said Jimmer type player and correct him to Ben Wallace, but Jimmmer is already a star in the US but most people don't know him that good outside of it i believe,
Also i expect the NBA to give defensiv qualites a higher rating then the basic offensiv one, which should be the same like here in my eyes. If you get a great offensiv player he should have at least a solid defence, but you could put him a great defender without a solid offence.