cadian flak and carpace are mad of the same stuff, carapace just put more of it over more of you.
No it’s not.
Here is knight, landsknecht and hoplite armor. Knight and landsknecht have steel armor, hoplit bronze, but landsknecht and hoplite armor % covereage is more alike and much less than knight’s.
Same thing with kasrkins, arbitrators, scions - they have different coverage and style but same material - carapace, which is a composite material that includes ceramite. It’s just specific sets, mostly cause you need to distinguish small soldiers on your table. And so you rarely see full flak set anywhere, cause arts most of the time depict minis. And cause of that carapace is kinda synonymous to kasrkin, scion, arbites armor.
From the lore perspective some hive ganger or bounty hunter can put carapace vest + flak helmet + flak bracers + flak greaves. Or some planet governer can have a pair of bikini panties one made of carapace and one of flak both look indetical cause local fashion.
The same principle is used in the production of Guardsman helmets and bracers. Guards for knees and legs are also produced
New cadians have knee pads for example
