I'll be offering some thoughts on why I think Nokia 17 should be Low 2-C but first the important bit;
Ribrianne could push back Base Goku, so she's probably 3-A unironically
Anyways, lets begin.
We actually have a statement from Frieza implying that 17 wasn't going all-out during his fight with base Toppo, which is actually consistent as he was mostly fighting to stall and given the feats we would see from him later.
The statement actually gives
A LOT of validity as it explains how 17 seems so much stronger in such a short of amount of time.
17's attack on Jiren was
by far the most potent attack Jiren had taken at that point in the tournament.
It was the first time he had taken damage on that kind and the 2nd time an attack had left a visible mark on him since UI Goku 1 (which was a literal scratch compared to the actual scar in his suit that 17 gave him)
Neither SSBE Vegeta, nor SSB Goku did damage of this calibre on Jiren (who are both listed at Low 2-C)
We actually saw base Frieza attempt a sneak attack on Jiren right after Vegeta, Goku and 17 had all been beaten which amounted to nothing and ended up getting him demolished right after.
So you do need relevant strength for a sneak attack to deal damage comparable to what 17 did. The only real exception to this is the Sorbet feat (which is extremely bizarre for a dozen reasons)
So 17's feat being a sneak-attack does not invalidate it by any means.
I mean, 17 did literally one-shot the fatigued Jiren that was equal to Golden Frieza. So saying it did nothing isn't really accurate. But I agree with the rest, this does not scale 17 nor Frieza.
Concluding this as plot convenience seems even more bizzare than just taking it at face value for me. There's half a dozen feats that would have to been converted to outliers for the sake to consistency then.
- 17 taking hits from Jiren must be an outlier
- 17 pushing back Jiren with his ki-blasts must be an outlier
- 17 taking hits from GoD Toppo must be an outlier
- 17 keeping up alongside SSB Goku and SSBE Vegeta must be an outlier
- 17 briefly clashing with the Jiren that Goku and Vegeta could clash with, must be an outlier
- 17 hurting Jiren with the suprise attack must be an outlier
If we wanna leave this for another time, that's fine by me (I will admit that this post is probably uneccesary instigation, as it's unlikely to change opinions)
But i'm really not a fan of this conclusion at all, judging so many feats as inconsistencies just ends up making any proper scaling extremely cluttered.
Especially as there are statements that explain the original feats, which ends up going against the idea that these are outliers.