Yeah, there's a lot to unpack here.
The way medieval artists use patterns on fur does evolve a bit over the centuries. You're more likely to find something that looks scalloped in earlier, more stylized manuscripts.
What you say about the direction of the "scales" is mentioned from time to time, but it isn't said nearly enough. Take
any form of scalloping in medieval art, and they have a way to run from the "top" to the bottom. Medieval artists knew how to follow this, from snakes to roof tiles to feathers to armor. So are we really supposed to be looking at scales, or rather series of curved lines indicating rough fur?
I don't know the answer to this, by the way, I changed my mind like ten times about what I think this thing may have been intended as. But we have to start from observation, and I am just not sure that these were intended as scales.
There may be some evidence in the MS. The fish from Pisces get correctly oriented scales. But guess who
does get three bands of curves pointing the "wrong" way? White Aries. They even used the same pigment and "painting technique" in the green one, though I understand the linework itself should be more convincing to some.