Not all armor is created the same, some is made from sterner stuff, others, not so much.
The Petty Kingdoms is a region consisting of hundreds of small states. Some are kingdoms, some are city states, some are large farming communities, some are duchesses and baronies and so on and so forth. Within a few miles the PCs might reach a new "country" with completely different rules and norms than the one they left behind. "What do you eat here? Humans ye say? Lets turn around fellas."