Here's the problem when bringing up Heroes of the Storm in relation to League of Legends: Both games occupy different sorts of balance space that, in their own ways, make both games unique.
League of Legends has every champion with some degree of uniqueness fitting into their Classes and Subclasses, always bringing something interesting to the table - for example: Talon and Katarina are both Assassins, but Talon excels in roaming assassinations, Katarina excels in blinking AoE assaults that require strategic positioning, preparation, and improv work.
Whereas Heroes of the Storm has their Heroes with all sorts of unique and widely varied playstyles that more-or-less get generalized into one of four Classes, allowing them more liberty to stray from the norms and play around with truly, truly unique kits. Like for example: Varian is Multiclassed as a Warrior and an Assassin, depending on which Lv10 Talent you take, or Cho'Gall who literally requires two friends to play him, and more or less looks stupidly hilarious if they're not on comms.
But, again, that's where the schism has to be addressed: Heroes of the Storm actively does its best to deliver vastly unique and otherwise unheard of kits with their Heroes, whereas League of Legends actively does its best to ground kits and playstyles into a more strategically diverse but uniform way.
You'll have a lot of Juggernauts who play in similar ways (Lane sustain making it either a battle of aggression or attrition), but in Heroes of the Storm, you'll have three Warriors - for this example, I'm going to say Artanis, Chen Stormstout, and Sonya - who all play differently in unique ways.
Artanis, for example, is a duelist sort of Hero, who primarily survives and tanks damage by executing high strings of auto-attack combos, as well as working to displace enemies with his Phase Prism and Blade Dash. Chen however is a threat of attrition, doing mediocre damage and requiring to combo his Keg Smash and Breath of Fire to do DoT damage, but his general inability to take damage thanks to his Brewmastery makes it apparent that he is still a threat, regardless of what little damage he does. And then Sonya is great at forcing enemies out of lane, since she can generally thrive as long as there's enough minions nearby for her to heal through Whirlwind, and she can do an impressive amount of chunking with her Colossal Slam and Ancient Spear.
But, again, my point is that trying to compare the uniqueness of Champions from two different games of the same genre - one which tries to deliver unique play and one which tries to deliver uniform play - is kind of a poor idea from the gate.
