I am Con then...
WARNING THIS IS SENSITIVE MATERIAL, THE IMMORALITY IS NOT EASY TO DIGEST
I will represent Nairobi. This was a very clever bait and switch by me because unless you knew some crucial scenes, it's hard to kill Tokyo's overall positivity (not a concession)
NAIIRRRRROHBEEEEE let's teach these putas what the matriarchy is really about.
When Tokyo harassed, in fact sexually assaulting and almost raping an underage high school girl in a scene where she was going to force someone who had possibly got a crush on her (Tokyo's) lover, Rio, she became so utterly furious that she forced this girl up against the bathroom/washroom mirror when other went out, held her assault rifle up to the girl and was going to make her make out intensely with her.
Then... In walks Nairobi to the female washroom/bathroom.
She holds her gun firmly, not pointing it at Tokyo but making clear she is ready to use it, stares sternly into Tokyo's eyes and lets Tokyo gather herself and leave willingly knowing Nairobi aint noone to fuck with where immorality is concerned. After Nairobi is alone with the girl, she makes the girl stare into the mirror, asks her what she wished she could do that some authority figure in her life stopped her doing (turned out to be ballet dancing, her dad thought it was stupid) and then Nairobi makes the girl scream into the mirror over and over 'I am a boss' and such things until she burned with power.
This is one of many examples of how Nairobi's spirit truly is. She is in the heist to get money to convince the adoptive family of her son that she is no longer the waste of space drug addict who her son was taken away from her for being. She consistently keeps her cool, like a zen warrior who can't be shaken and unlike Tokyo, when they overthrow Berlin (which was only possible due to Nairobi, who had previously been completely loyal to him), she takes charge treating the Heist as a matriarchy and even forgives Tokyo for her troublesome ways that had screwed up the heist in a few ways.
Nairobi, furthermore, is extremely kind and merciful to her underlings in the money printing faction of the operation. She is the only one of the heisters to both be in a leadership position in several ways and yet never need to flex her guns or shit, she uses diplomacy, reason and level-headedness to ensure the Heist brutally overcomes one obstacle after another.
Nairobi is best friends with a gay guy who she helps overcome the trauma of losing his lover during the Heist, unlike Tokyo with her lust for Rio that is quite volatile to be frank.
When Berlin sexually assaults a hostage and attempts to completely rule as a Tyrant, Tokyo approaches him presenting herself as nothing but a troublemaking rebel-leader. She is everything he can use to paint his opposition as lunatics and while Nairobi initially opposes Tokyo, she is also the only reason he was unable to successfully sexually assault the hostage, due to cues Nairobi picked up on that led her to be in the right place at the right time.
Let me be clear, there were two sexual assaults halted by Nairobi's presence in a situation that she had every justifiable reason to not have noticed or been at (as all the others did). Nairobi is also the only member of the Heist to never once let her biases even for her best friend Helsinki, interfere with her conduct in the operation. She is smooth-operating, adaptable yet merciful and an extremely effective protector of the victims within the Heist.
I also believe that Arturo's rebelliuos, disastrous antics were only helped by the chaos Tokyo began to cause during the heist, which were often for half-selfish half-selfless reasons. Meanwhile, Nairobi was the only member of the team (yet again only member) that Arturo had zero beef with.
Furthermore, when Berlin is falsely framed by the Spanish version of CIA, for being a human trafficker and pedo-assister, the entire Heist crew begin to want to rip his head off, Tokyo most of all. It is only Nairobi who both takes into account the false report (helping her to correctly, perhaps accidentally, spot a sexual assault Berlin attempts later) but furthermore keeps her cool and stops the in-fighting because she instantly realises what the intention of the News report was, even if it was true.
This could be seen as morally questionable hypocrisy but is actually her putting the group's wellbeing and success above any obstacle and malefactor that arises. It is also safe to say that Nairobi is extremely well-liked and respected by her team. Even Berlin who was hit in the back ofhis head by her gun during the Matriarchy coup respects her and is loyal to her in the aftermath. Unlike Tokyo, Nairobi doesn't constantly 'fight evil' instead she 'tames evil' and that is far more effective and morally positive. There is never a point in the Series' Part 1 and Part 2 where you can even call her remotely evil, in my opinion.