Agree I never saw the 140cm Kachinas in these cws but I am always very skeptical of having that as my ONLY reason for doubting a scarf. There are too many rare variants these days ...
Everytime I think that I know all the cws, I discover a new one, typically sold only in one foreign market - not widely across the globe. Ex of this: the hot pink Jungle Love Tattoo, sold only in Japan identical to the 3 cws that everyone knew about - red, orange navy and there are JL Tattoo fakes all over, so, I thought the pink was fake when I first discovered it.
PS Not so much for Kachinas , as it only came out once in 140cm summer twill silk - as you said, but the super popular ones - Brides de Gala - Ex Libris have such confusing 140cm variants - dip dye , summer twill, twill, twill lave etc Hard to tell them apart in photos if tags are gone, & photography is bad ... (a mod shot of the scarf is useless for that) so, I often wonder when seeing a 140cm if it might be an unknown cw in some relatively rare variant ...
PPS on rare variants, see last posts in authentication thread about mousse Ex Libris . Hermes has lways had some mutant scarves come out of their scarf production.