Warlocks can one shot melee in radiance yes but what else do they have? I mean all other supers have the ability to one shot people. I think the Titan punch doing below base damage is that overload perk, kinda like explosive rounds will deal less than its base impact damage cause it spreads it in an area. Plus melees are bugged to shit right now anyway, I've had instances where my melees don't proc at all on all characters and sometimes my melee kills in one shot across all characters. The worst experience is my Titan. I have many videos of me punching a guy on minimal health and it doesn't do any damage.