If Kihira gets one reliable quad, everyone else is in big trouble. Being able to do a 3A instead of a 2A in the SP is a big advantage, and I don't think any of the women doing quads are on Rika's PCS level (yet). With one or two quads and one or two 3As in the LP, a clean Rika would be hard to pass with her SP advantage. Mathematically, someone like Trusova could do it, but three quads and no 3A over two programs might not be enough to top one quad and three 3As over two programs if the PCS scores aren't close.
I disagree.
First, there is a matter of consistency - if Kihira`s 4S is as stable as her 3As, she can just as well lose to a bunch of girls with no quad or 3A at all.
As an example, lets look at her 3A in short last year (short because no mess with combo success rate factored into it):
Nepela: 3A fall, 3.00 (with fall deduction)
NHK: 3A< fall, 2.00
GP France: 1A*, 0.00
GPF: 3A clean, 10.51
4CC: 1A*, 0.00
Worlds: 1A* 0.00
The average is 2.58, which is less than a clean 3A
But ok, suppose its a game where everybody skates clean. Jumps only.
Trusova`s TES in SP: 2A, 3F, 3Lz+3Lox = 20.48 + 4.97 GOE she got at Nepela
Trusova`s FS, cleanish: 4Lz, 4T+3T, 4T, 2A, 3Lz+2Lox, 3Lz+1Eu+3Sx, 3Fx = 63.96 + 12.39
Trusova`s FS if clean: 4Lz, 4T+3T, 4T, 2A, 3Lz+3Lox, 3Lz+1Eu+3Sx, 3Fx = 67.48 + 14.99
Total if clean: 25.45 + 82.47 = 107.92
Kihira (using ACI as reference, and her free at NHK last year, which was her best scoring FS):
SP: 3A, 3F+3T, 3Lo = 22.89 + 4.28 GOE at ACI
FS: 3A+2T, 3A, 3F, 3S, 3F+3T, 3Lz+2T+2Lo, 3Lo = 52.53 + 12.09
Total if clean: 27.17 + 64.62 = 91.79
Also, keep in mind that Trusova hits her levels, so there won't be a huge difference in other elements. The only difference would be PCs, really.
So, Trusova loses 2 points in TES in SP (she backloads her combo, and has a 3Lz instead of a 3T, that makes up for a good part of the 3A advantage).
And in the FS, Trusova has an advantage of 18 points or so, due not to quads only, but also to an overall much harder layout.
Now, 4S BV is 9.70. It would replace a jump though, so its not like full BV and GOE will be added. Assume thats a +6 (4.5BV + 1.5GOE on top of her 3S) points to Rika, and still a gap of 10 points between both girls.
Lets look at their PCs.
At ACI, Rika got 34 + 69. That is what she was getting last year too, so its not like it is an exceptionally low score.
At Nepela, Trusova got 32 + 65.
An advantage of 6 points for Rika compared to a girl competing in seniors for 1st time. Bad news, Trusova's PCs will raise.
Mathematically, Trusova's quads, backloaded combos, 3Lzs across 2 programs beat Rika's 3x3A and a 4S.