I was having debate with one of my players about a possible upcoming scenario and I would love some input. He is a multi-classed Sorcerer/Warlock and at some point soon hopes to use the darkness/Devil's Sight combo. The party also includes a Ranger/Rogue multi-class and she makes great use of her Sneak Attack.
Now I understand that if all creatures, both friendly and hostile, are in darkness then all advantage from unseen attacks and disadvantage from being the target of an unseen attacker cancel out, creating a level playing field (a bunch of people blindfolded with sticks have an equal opportunity to hit one another.)
The issue I'm running into is this: Is the Rogue able to use her Sneak Attack even though she is in darkness?
My initial thought was no, because even though according to the RAW it's a level playing field and she should still be able to do things like do an extra 1d6 damage on an attack if the hostile creature is within 5 feet of her allies etc.; thematically I'm hitting a wall because it's a skill that assumes the creature (let's say a bugbear) is being distracted by an ally (let's say our Dwarf Paladin) so the rogue takes advantage of that distraction and zeros in on a vulnerable spot and gains the extra 1d6 of damage.
But in darkness, the bugbear can't see the Paladin to be distracted or engaged in the same way he could in light, and the rogue can't study the bugbear in darkness and is essentially using her hearing and firing a shot into the dark. So it makes little sense to me to allow the use of certain skills that rely on such thematic precision even though total darkness for all creates a level playing field (except for the Devil's-Sighted Sorlock who is running around wreaking havoc).
In this scenario, the only player with Devil's Sight would be the Sorcerer/Warlock. The other three players (Rogue/Ranger, Paladin, Bard) would not have vision in darkness and while it is a useful strategy for the Sorlock, he has concerns that it would nerf the other players' abilities and we wanted to get a clear answer before this scenario presents itself.
I do know that as DM I can rule one way or the other but, as cheesy as it sounds, I like to create a game where all the players feel a sense of ownership and agency in the world and would rather not slam down an iron monarchical fist and instead get input and make a decision. I should say that I do value thematically believable RP in my games fairly high.