I was actually using the role they’re given on the Battleborn website, which seems to list Attackers are the squishies that do damage (including Marquis), defenders are the tanks and supporters are, well, that. It’s not so much to do with whether they’re good at attacking or defending a point. Recently they added characteristics that define a character’s strengths, for example Marquis is an Attacker who’s characteristics are territorial, sniper and advanced.
Attackers - Marquis, Deande, Trevor Ghalt, Mellka, Benedict, Caldarius, Orendi, Oscar Mike, Phoebe, Rath, Thorn
Defenders - Attikus, Deande, Toby, ISIC, Boldur, Montana
Support - Ambra, Reyna, Miko
If I were to hazard a guess, I’d say that Whiskey is an Attacker, Kelvin is a Defender and Kleese is a Supporter. I would have pegged Shayne as an Attacker and El Dragón as a Defender because of their ability damage and cc, but I just double checked their videos and El Dragón has a health pool like Whiskey’s and pretty nasty damage output at times, while Shayne’s health pool was huge by comparison. It’s just odd because El Dragón has knockups, a stun, ways to slow or reduce an enemy’s damage output, but he only has 1000 health at level 1, like Whiskey did in his Let’s Play. Shayne has some pure damage moves, stealth , limited cc and her ult even depends on team cc in order to do something worthwhile in my opinion, yet her health pool in her Let’s Play starts off around 1700.
Maybe it’s something to do with El Dragón’s video being PvP, while Shayne’s was a 3-man story mission. Foxtrot’s was a 3-man story mission too, though.