And yet ‘staunch’, while technically not entirely incorrect in this context, is markedly less correct, and jars on anyone who knows better.

As far as the use of ‘loading a bow’, it could indeed be a colloquialism peculiar to the era … only, it isn’t. Collins reliably identifies and explains the actual colloquialisms in her work; this one clearly is peculiar to her. (One can load a crossbow, but not a longbow.) Again, while not specifically wrong, it catches the attention, and when a reader is asking, Is that right?, he/she has been jolted out of the story.

I’m not criticizing Collins’ writing skill as such (truth be known, I’m deeply envious of her), but of small, relatively rare, but grating errors.