Scale Armor & Accuracy

[Gaius Julius Caesar]

Well, logic would dictate you overlapped on a 50/50 basis, to give good protection against penetration.
But, apparently not....
You could expalin it as the officers requiring a lighter armour, especially when on foot, as they may be required to hasten about the lines moreso than the foot soldier, who will have to stand and fight....but it seems to be the comon thought that even squadies wore scale....
So, your guess is as good as any!