Wait, do the Sub Maps have their Own Themes? 
I can Name them off from the Pictures, but if they have Different Themes, then no Clue.
I just Remember the 5 Original Tanks and Name the 7 Release Tanks in Order, then I do the 3 Release Supports and their 7 Releases in Order, then I do the 17 DPS in Pairs, with Symmetra on her own.
So Reinhardt, Zarya, Roadhog, D.Va, Winston, Orisa, Doomfist, Wrecking Ball, Sigma, Junker Queen, Ramattra and Mauga.
Mercy, Lucio, Zenyatta, Ana, Moira, Brigitte, Baptiste, Kiriko, Lifeweaver, Illari.
Widowmaker, Reaper, Sombra and Junkrat (Villians, I used to Include Doomfist but he’s a Tank now), Soldier: 76 and Sojourn (Boring Super-Soldiers), Hanzo and Genji (Obviously), Pharah and Echo (Flyers), Tracer and Mei (Remaining Good Guys), Torbjorn and Bastion (A man and his Pet Dog or something), Cassidy and Ashe (Cowboys) and Symmetra (Forever Alone).
It also Helped that I could go back and Count how Many Heroes I have here, else I’d have to use my Fingers.