Somehow I've managed to overlook this for years:
Compare his legs to the similar left-handed attacking sprite:
Or the normal standing animation, for that matter:
Every animation of his sprite is consistent with those, except for the normal walk animation and half of the right-handed attack animation because they share the same back leg sprite. The first thing that came to mind when I saw this was Cecil from the SFC boxart:
The unarmored legs on the walking sprite are very similar to that. The palette is obviously wrong but I think it's plausible those legs are a leftover from an earlier Cecil sprite design that mimicked this artwork, these two tiles somehow didn't get updated when everything else did.
Another interesting thing - they actually bothered to fix it in the GBA version:
Pretty half-assed fix, they just reused the legs from the left-handed attacking sprite rather than drawing a new one with the bottom outline of the hand and arm and the back of the cape. Still, got to give them credit for bothering at all.
We have EVEN MORE themes now, but some old ones are gone...