No, David Archy and Separatec are not the same.
David Archy is a men's underwear company that offers a wide variety of underwear styles, including boxer briefs, trunks, and briefs. Separatec is also a men's underwear company, but they specialize in boxer briefs with a patented design that allows for easy separation of the legs (hence the name).
So while both companies make men's underwear, they each have their own unique offerings that set them apart from one another.