Let's start quantitative, since that's always the easiest to argue. As it stands, the number of unique characters each class has representing them as hero portraits is:
- Demon Hunter: 3
- Druid: 5
- Hunter: 3
- Mage: 5 (including Lady Prestor)
- Paladin: 4
- Priest: 4
- Rogue: 2
- Shaman: 6 (including Ragnaros)
- Warlock: 4
- Warrior: 5
In a game where all classes play an equal role, generally get an equal number of cards, and over time get a more or less equal amount of time in the spotlight, having that much variation between classes in anything is pretty weird. We can dismiss DH's low count by it only having been here for a year, but hunter and rogue having so few compared to several classes is tough to explain.
Certainly it's not a problem with limited class fantasy. For rogue especially, you've got rogues filling the role of thugs, thieves, crime lords, spies, assassins, ninjas, pirates and more. Certainly there's scope for overlap in that, but there's also a lot more variation in themes and flavour than, say, a mage who chooses to use a different spell school, or a paladin who… let's face it, there's not much variation within paladin since it's a niche combination of priest and warrior to begin with.
It is somewhat amusing then, that rogues are represented by Valeera (a female elf who's a lawful good spy, ex-gladiator and messenger between the Horde and Alliance) and Maiev (a female elf and lawful good warden/jailer (yep, she's technically not even a rogue)). Not exactly ticking many of the rogue profession boxes there. Love it or loathe it, the Cap'n Valeera skin is all we really have to start representing the less lawful side of the class whose name actively specifies they are outside of the law.
To be honest, getting Mathias Shaw wouldn't help tick many boxes either. We'd get a lawful good male human spy, so that's a hooray for gender and race diversity but doesn't add much new elsewhere. Someone like Gallywix or Lilian Voss would be better, but the ship already seems to have sailed for them.
All this makes it especially frustrating the rogue only has 2 heroes. Where possible I like to set my hero and card back to fit the themes of a deck, but the range of options in rogue is sorely lacking for that.
