Notes:

Alternate captions include Stukov, any of the notable Diablo bosses, and Grommash hellscream.
Seriously though, in the past year we've had a whole 2 starcraft heroes, one of which happened during a starcraft themed event, that's right, we got 1 starcraft hero in a starcraft event (the other was Zarya but that's only slightly relevant)
Overwatch will have had that much representation within this month, and has had 5 characters brought in within the year
pales in comparison to warcraft but there's got to be some kind of priority for universes that have a big selection to pick from.