Modern terminology for armour is notoriously misleading. ('Chain mail' and 'suit of armour' are two cringe-worthy common examples.) In this case, brigandine might have been a reasonable historical description, although, given the leather composition of the armour, cuirass might also have been an appropriate choice. The reference to 'studded leather', was intended merely as a broad, 'layman's description' of the armour's construction, rather than an accurate nomenclature, as one might have heard uttered in a mediaeval armoury.
In any event, neither modern nor antique classifications much help us to identify the sections on the bracers, boots and shoulder. I rather suspect these are unique to witcher armours, designed by CDPR, since I can't recall ever seeing a close enough real-world historical equivalent. However, the function of these elements appears to be similar to that of 'coat of plates' or 'splinted' reinforcements, although in traditional armours, broader strips of steel were used, rather than slender rods.