Even though it's not written this way -- host spots are down the list in the announcement -- I think they declare their host picks up front, so that the rest of the Feds know when a skater/team has one. I don't think they get to declare them later.
I think so too, but I also think there winds up being some horse-trading going on - and I'm not sure if it's all the host picks that are declared up front or just the seeded/invited ones that wind up being host picks.
There's also the part which isn't written but we have testimony from skaters that this is so: at least the seeds get to list their preferences, so that, after host picks are assigned, Kagiyama, Chiba, Conti/Macii, and Fear/Gibson get what's left in Round 1 and Sato, Higuchi, Efimova/Mitrofanov, and Smart/Dieck get what's left in Round 2, based on the selection order each Fed draws for each discipline.
I think once, the Japanese Fed picked two skaters in the same 1-3 or 4-6 group, and one of the other Feds chose two from the next group. I know it happened a couple of times in the later groups, but by the time it's 7-12, I'm not sure many people care. And I don't think either was recent.
Looking back over the past two seasons - there haven't been many instances of a host fed having 2 skaters/teams in the 1-6 seeded group, let alone 3 skaters in the 1-6 group.
2022-23 GP
Men - Uno 1-3, Kagiyama 1-3, Tomono 4-6
Women - none
Pairs - none
Dance - ChoBat 1-3, HawBak 4-6; GilPoir 1-3, FBSoer 4-6 (HawBak, GilPoir & FBSoer all moved up to seeded status following retirements from PapCiz, HubDon & SmaDia)
Uno was assigned to SCI & NHK (3 weeks apart), Kagiyama was assigned to SkAm & GPdF (2 weeks apart), Tomono was assigned to GPdF & NHK (2 weeks apart)
ChoBat were assigned to SkAm & NHK (4 weeks apart), HawBak were assigned to SkAm & Espoo (5 weeks apart)
GilPoir were assigned to SCI & Espoo (5 weeks apart), FBSoer were assigned to GPdF & NHK (2 weeks apart)
2023-24 GP
Men - Uno 1-3, Tomono 4-6
Women - Sakamoto 1-3, Mihara 4-6
Pairs - SDDes 1-3, PerMich 4-6
Dance - ChoBat 1-3, GreenP 4-6; GilPoir 1-3, FBSoer 4-6
Uno was assigned to CoC & NHK (2 weeks apart), Tomono was assigned to SCI & CoC (2 weeks apart)
Sakamoto was assigned to SCI & Espoo (3 weeks apart), Mihara was assigned to CoC & NHK (2 weeks apart)
SDDes were assigned to SCI & CoC (2 weeks apart), PerMich were assigned to SkAm & GPdF (2 weeks apart)
ChoBat were assigned to SkAm & Espoo (4 weeks apart), GreenP were assigned to SkAm & CoC (3 weeks apart)
GilPoir were assigned to SCI & CoC (2 weeks apart), FBSoer were assigned to GPdF & Espoo (2 weeks apart)
2024-25 GP
Men - Malinin 1-3, Brown 4-6
Women - none
Pairs - none
Dance - GilPoir 1-3, LajLag 4-6
Malinin was assigned to SkAm & SCI (1 week apart), Brown was assigned to SCI & NHK (2 weeks apart)
GilPoir were assigned to SCI & Finlandia (3 weeks apart), LajLag were assigned to SCI & CoC (4 weeks apart)
The USFS seems to routinely, actively assign both of their seeded ice dance teams to Skate America - they did it with HubDon & ChoBat a couple of times and they've done it with both ChoBat/HawBak and ChoBat/GreenP in this Olympic quad alone, so it's a safe bet to presume they'll do it again with ChoBat/CarPon.
The only example we have of a country with 2 skaters in the same seeded sub-group was Uno & Kagiyama in 2022 - the JSF chose to keep them apart. Meanwhile, Tomono, who was in the lower seeded sub-group wound up initially scheduled against both of his compatriots - Uno at NHK and Kagiyama at GPdF.
From that, we can probably guess that Sakamoto & Chiba will be kept apart, while Higuchi may very well go up against both of them separately. Based off this information, the most likely breakdown for the Seeded 1-6 Women will be as follows:
SkAm - Liu & Glenn
CoC - Sakamoto & Levito
SCI - Chiba & Glenn
NHK - Sakamoto & Higuchi
GPdF - Liu & Higuchi
Finlandia - Chiba & Levito
In some regards, it almost doesn't matter what the seeding is, because the women's fields are going to be ridiculously deep between there being 3 Japanese women and 2 American women at each event plus 2 each of the 7-12 (Pinzarrone, Petrokina, H Lee, C Kim, Schizas & Repond), not to mention Gubanova, Gutmann, Samodelkina, Jia Shin, You and maybe Hendrickx.