You actually got a laugh out of me with that but you you do know that most Beastmen gear is a haphazard thrown together collection that only sometimes fits them and that the stuff you could say was made for them could come from the Chaos Gods considering for example that Chaos Warrior armor is a unique "Gift" each Warrior gets from the Gods. I could easily see the Bestigors getting some of their equipment by way of Blessings of the Dark Gods. Regular Beastmen Gors standout for the poor quality of their gear which is why those dedicated to Tzeentch standout for having swords and axes that look they had actually skill put into them or a unearthly elegance.
Also when I said they steal and loot a lot of their gear I was not referring to just humans, they will steal from and loot bodies of everyone they fight which is every other sentient and non-sentient group of living things on the planet. They also some times trade with other Chaos factions but I doubt that they are any better then Orcs when it comes to making things themselves which is really bad to say the least. Goblins are better then they would be and even they aren't very good at making things.
Ah, I see! You are proposing a third scenario - that is to say, one you have invented entirely out of wholecloth - whereby Beastmen perform sacrificial rituals and undertake great deeds before the eyes of their dark gods, in exchange for
random mundane axes and pauldrons popping straight out of the Realms of Chaos and into the forests outside of Bechafen like they're goddamn loot drops in an MMO.
The problem you are running into is that Beastmen, as a faction, are explicitly written as a parallel to the Germanic and Gallic tribes faced by the Roman Empire - or rather, to their portrayal by the Romans, who tended to depict their "barbarian" opposition either as unstoppable supermen who traded sophistication for honour and insight, as cunning wretches whose innate dishonesty could sometimes be mistaken for cleverness, or as crude savages incapable of higher thought or craft. The specific choice of portrayal flip-flopped depending on what made Rome (or the writer) look better at any given time, but we as semi-objective readers of history can clearly see that a) none of these things were true, because if they were then these people couldn't have done the things they did, b) even if one of these things was true, they can't
all be true at the same time.
So Beastmen are intended to evoke the Imperial (and pop cultural) portrayals of certain ancient peoples. However, this means that Beastmen have to be able to
accomplish some of the things those ancient people did, while also being described in ways that
would make accomplishing those things impossible, because those portrayals were self-aggrandising Imperial propaganda that lacked any internal consistency. Beastmen are stupid and respect only strength, but also clever enough that their army rules revolve around launching ambushes that no other faction can pull off. Beastmen are crude and incapable of actual craft, but also have bespoke armour and weapons, and famously ride chariots specifically made for mutant animals. Beastmen are animalistic and barely even possess a real language, except they
do have a language, and by the way here's the alphabet complete with a writing system, and also they seem to be quite commonly multilingual.
You are relying on the Sigmarite Empire's portrayal of Beastmen to be the full and complete truth. This will never make any sense, because it is based on real-life Imperial portrayals of barbarians, which
also never made any sense.
You also seem to be referencing the model design of Tzaangors? These were released for Warhammer Age of Sigmar, and exist in an entirely different setting as part of an entirely different culture. There's never been a Warhammer Fantasy Tzaangor design that wasn't just "Blue Bestigors".