In SK, the net result overall is to remove a dangerously errant Summer Lady and restore the balance.
In SmF, the net result is to keep the Archive from falling to the Denarians, which benefits both courts. And Mab makes it clear to Harry that Summer's forces opposing him are not there to stop him but to compel him to be Winter's Emissary for this job when she can't (by her own given word in SK) do so herself.
Both of those results benefit the world in general so yes if you wish to attribute it to Summer and Winter both coming out equally I suppose
technically you are correct. But originally you made it sound as if Mab's actions end up benefitting both Courts almost by design, I very much disagree with that notion.
Their Knight is killed by their own rogue Lady. And killing rogue ladies is not a loss to the Court they belong to, that I can see; they get replaced.
It really doesn't matter HOW they get killed, they still died. Aurora is replaced by a totally inexperienced and unprepared Lily, who just a few short years later herself is led to her own downfall. And she was not Maeve, Aurora still fulfilled her role for all those centuries. Ronald Reul who would have been a match for just about any Winter Knight over that time period is replaced by another novice who takes several years to come into his own confidence and power, who lost pretty much all his friends and NOW has lost his lady and the woman he was probably in love with. Now they have another Lady who never wanted that kind of power, even if she was born to it and I happen to actually be of the mindset Sarissa will be good for both Summer and Titania in the long run...still doesn't change the fact that its going to be a rough transition for her.
But no matter that these roles get filled, it cannot be good for the stability of a powerful faction to keep rotating out all their experience from the most important positions every decade or so when an enemy like Nemesis is lurking. And clearly Aurora's death, while 'necessary', pretty much killed Titania's will. Harry goes to her and asks for help when he doesn't know whether to believe Mab or Maeve and she basically shrugs him off saying she no longer cares if the world dies, HER world died in her mind. What if Mab does for some reason get infected, who will protect humanity if not Titania when that's her whole purpose?
So yes, the Summer Court gets shafted a whole helluva lot and to me whatever slight benefits they may have gained are far outweighed by what they've lost in the past say 15 years...even more obvious when you see how much Winter has gained.
None of the gruffs up until Eldest are particularly plausible challenges for Harry, and Eldest basically slowly gives Harry hints until Harry figures out how to get out of the situation; this is not the action of an Eldest-level entity that wants Harry dead and is not an idiot.
Tiny gruff was more than a match for Harry but the Hobs helped get him out of that, the other hitters could have gotten him too if Thomas hadn't come along so lets not discount that they weren't a match for Harry, he was pretty well on the ropes.
Harry cites it as specifically feeling like the mordite he dealt with in DM.
Like I said, i'm fine with the belief that Raith is protected by Outsiders...but Harry's FEELING is not an explicit notion that it can only be Outsiders like you made it out to be.
Harry offers that as one possible theory alongside external corruption, and is not at all sure of it.
Not being sure doesn't preclude the option, just means there's still some information about it that needs to be resolved.