Corbridge A Breastplates - to cross or not cross diagonally?

[sulla felix]

And as you and Barry have to bear in mind, the internal leathers
are what are supposed to allow for the plates to flex relative to each
other wherever the internal leathers are placed. If you ain't got
internal leather between plates, then they ain't supposed to flex at
that particular junction! Look at the shoulder guards - they have
internal leathers to allow them to flex. Look at the abdominal plates -
they have internal leather to allow them to flex. Look at the junctions
between the two pectoral plates - no internal leather
That's becuase they were not designed to flex relative to each other
They were just meant to hang there in a vertical position. And this is
the clue as to what shape the subarmalis must have been - so as to
allow the plates to hang vertically.

Neck opening size? Hange the plates vertically and it decreases dramatically, as ably demonstrated by Tarbicus and Matt.