In-world background: As part of its army, Country Bad Guys has a contingent of human slave cavalry. Country Bad Guys wants these humans to have an armor that will provide reasonable protection, but also not be top-of-line in case these humans revolted. They decide that they will give these slaves armor of human leather made from disobedient slaves as a reminder of Country Bad Guys' power. (Whether or not that idea is effective is beyond the scope of this question.)
Real-world background: I know that leather products have been made from human skin. I've also learned that historical leather armor made from cattle came from a specific part of the cow, the back where the hide is thicker. This latter piece of knowledge is the main reason I ask if human-leather armor is practical as I don't know if there'd be such a practical spot on people.
Question: Using Medievalesque technology, would it be possible to make useful armor out of human skin? And would it be practical?
For useful, I define that as providing at least around the protection-level of gambeson and or historical leather armor. For practical I define that as not taking more than 10 people to make it from. (Country Bad Guys can't be killing all of its slaves.)
Some ideas I've thought about that may or may not be good starting points in answering the question:
1: Scale/lamellar leather armor allows for smaller pieces of leather to come together in a suit of armor, possibly decreasing the negatives of not having a ton of skin per individual to work with.
2: I thought about Ancient Greek armor and how they glued layers of linen together to create linothorax. I have to wonder if this might apply as a potential method.