Annotated 26-12
Even in her weakened state, we couldn’t have Rachel go down too, too easily, even if that meant we had to treat her a little brutally.
Blair is not merely devious; she’s the best tactical thinker in this chapter and one of the best in the series. (She does have a blind spot, but we’ll get to that.) The retreat buys Hestia, their biggest gun, time to recover and leads Frigg, the other team’s biggest gun, into a trap that could well kill her and will take her off the game board for the duration.
Blair is also smart enough to know that she lacks Hestia’s charisma and can get away with more as a right-hand woman under current circumstances, but I expect that in the long, long term, sisterly loyalty wouldn’t prevent her from following the Westeros School of Career Advancement once Hestia made too many reckless choices (see chart).