I seem to remember Cousins throwing lobs to McLemore last season -- and it's tough to say that Blake is a better passer than DMC... they are both great passers for big men, along with Noah. I'd say you can make an argument that all three are top 3 passing bigs in the league, with strong debates on who is #1. I'd go with Noah, as he's been doing it longer. DMC has great court vision and excellent passing touch. He would have no issues throwing up lobs to WCS.
DMC has great handles, too. Yes, he's overconfident and forces the fast-break when he should not be dribbling against great guard defenders. The difference between Blake and DMC, imo, is Blake is quicker. But I don't see a glaring difference between the two players handles.
Here's a passing highlight reel of DMC for the posters who seemed to forget his excellent passing ouch. He can pass from anywhere on the court (and I mean anywhere!), not just from the post.