That doesn't really go like this
There is "Atomic pool" once skis are in factory. But once serviceman picks those skis, they are not "Atomic (or any other company) pool" anymore, but skier's pool, and there's no way anyone would let anyone else ski their skis. Sure, skis are still owned by company, and for majority of top racers (some Austrians are exception, as Austria has whole bunch of pool servicemen, but that's due other reasons irrelevant for this discussion), their servicemen are employed by ski companies rather then ski federations, and it happens from time to time, but only for (very) lower ranked skiers, that guys from company come and take skis that proved to be really fast and give them to higher ranked ones (not for race but for whole season). But in general skis are assigned to certain serviceman and therefore certain skiers. Most of servicemen have 2 or 3 skiers that they prepare skis for, and even between these skiers, who are with same serviceman and same ski company, there's now way they would ever "borrow" skis to other one. So no, there's no way Shiffrin would get Ledecka's skis for race, or vice versa. That BS from Olympics, that Ledecka was on Shiffrin's skis is just that... BS