I got stuck down a rabbithole of comparing scores and compiled a very long post of the many possible scenarios.
If Anna is clean in the SP, she can get 78 (which she got when she was clean at Europeans). Her most ambitious free skate has a layout of 2 quad lutzes and a quad flip (which she was attempting last season, though she never cleanly landed three quads in any comp). Her highest FS skate ever is 162.65 (at GPF, with a 4Lz-3T, a 4Lz<, and a 4F fall). If everything happens cleanly, she can probably get 178 in the free skate (Anna's clean 4Lz at SkAm earned 14.79 total points compared to the 8.81 points at GPF. A 4F with +2 GOE earns 13.2 points compared to 5.5 from a 4F fall, also remove the one point fall deduction, and add some increased PCS for a clean skate). That totals to 256, pretty close to unbeatable.
There's more guesswork for Kamila since she has never competed at an international senior competition. If Kamila is clean in the SP with a triple axel, she will probably score 82 at international comp. Rika can score 82-83 with a clean 3A in the SP, which is what I'm basing Kamila's guess off of. If she's clean with two quad toes in the FP at international competition, she will probably score 166. At Junior Worlds last year, Kamila stepped out of her 4T and scored 152. At RusNats this year, she was clean and scored 174, but we can assume that international judges are not going to give her 9.5 in PCS. More likely, as a senior, Kamila's going to have to build her PCS as all ladies do, probably starting from around 8.75 for clean skates. With this in mind, Kamila's max total score is 248. She's mostly hampered by having an 'easier' quad than Anna and Sasha.
Aliona's limit is pretty clear. With a triple axel in the short, she can score 85. At her clean skate with two triple axels at the GPF last year, she scored 162. That totals to 247. Yes, this can go higher with increased PCS/GOE and RusFed meddling, but that's true for all these girls.
Without a triple axel in the short, Sasha can probably get a 76 (she got 75 at Europeans with a step out on the 2A). In the free program, her highest ever score is 166 with three cleanly landed quads (4Lz, 4T-3T, 4T-Eu-3Sx) and a fall on the 4S, totaling to 242. If Sasha went clean with four quads in the free skate, she would break 174 (the clean 4S alone would add almost seven points in TES, and there would be no -1 fall deduction, not to mention the increase in PCS for a clean skate), which would total to 250. This is still not enough to beat Anna with three quads. If she added a triple axel in the short program, she would be able to score 81. With the 174 from the four clean quads in the free program, Sasha would score 255, narrowly losing out to Anna, but with a margin of only one point, my approximations could easily be wrong depending on the GOE and PCS on the day.
TLDR: At everyone's peak performance, it's a tossup between Anna (two 4Lz, one 4F) and Sasha (one 3A in the SP, two 4T, one 4Lz, one 4S in the FP).
1/2: Anna/Sasha (255-256)
3/4: Kamila/Aliona (247-248)