This is about rule number one, there are always exceptions, :-). You don't see them much and indeed a lot on momonari but there is no reason just to put such type of shikoro just on one type of helmet as a Momonari kabuto to my opinion. I remind one on Aoi art with another helmet, when I see another example I will share it with you. This is what I just found: nl.pinterest.com/pin/527976756295884885/
Thanks Mischa! Cool to see other examples, thanks for the links
It's interesting to me that it wasn't more of a widespread design, clearly it was practical so I would've thought manufacturing single plates that require essentially no lacing would've made for outfitting troops faster. Though, they do leave much more of the neck exposed!
What do you guys reckon, any idea why they were rare?