I haven't really been playing for very long, so I'm still learning the ropes to an extent. Out of the characters I've played so far, I've only really managed to get a grasp on playing Abathur, Zagara, Tychus, Raynor, Lt. Morales, Leoric, Kharazim, Zarya, and Auriel.
I'm going to keep practicing the characters until I have a more firm grasp of how they all work before I start teaming up with others.
If you know how to set up his build correctly, Leoric actually doesn't need a healer at all; his second ability can see to that easily. Of course, this is assuming you're not suddenly ganked by several heroes at once.
I've also been playing Heroes of the Storm for the last two months or so. I think it's actually pretty fun, and that means a lot coming from me since I'm not usually a fan of MOBAs.