That's not what the books have said.
Balance. Like thinking Harry should kill her daughter because he killed Titania's. The 'things the books have said' are things Fix has said', Fix and his fixation on Winter Knight as evil incarnate.
For instance, Fix's job is not to kill the enemies of Summer, but rather to keep alive the people Winter wants dead.
That not really a provable translation. Notice Fix got no orders to protect Maeve specifically after all.
Likewise Titania's ultimate job is not to counter Mab, but rather take her out if she goes astray. Not to go astray the other way or whatever.
No, it's really to act as a counter balance, hence why any time one acts the other acts in balance, sometimes in unison IN that balance. Titania is
capable of taking Mab out to act as a counter balance.... this specifically is in connotation to nuclear deterrence, which is in fact based wholly on the idea of counter check/checkmate. She is literally the counter balance. The Scales that Marcone comments on, THAT is a mechanism for balance.
It's really quite simple though, the courts balance themselves in reality so as to not give the dark inversion of of our reality purchase to act... go read up on the Jewish cabbalistic order of Seraphim, it explains the base mechanics well enough, even how Satan was later replace by his 'wife' and easily meta's into Nemesis the actual Planet that's a dark mirror of ours thought to have brought about major extinctions on our planet. You could easily take the retirement of the original MS to be the original creator, who came down in human form as TWC and became a different role in reality later. This leave MS able to take over the abdication and the mirage to take on a female duplication... though I assume at some point it was male/female dualities, and that should be coming back around in this variation.
