I think alot of the problem is that the other gear sets are harder to make, which is why we don't see much of them at all. Crafters seem to really just be selling hempen/cotton cowls, Sheepskin/dodo harness stuff, and haubergeons. I know for lancers, the Haubergeon is practically the only LNC suited armor thats easy to find.
This. The Scale line of armor looks better and is usable at earlier levels, but is a pain to craft. Bone scale mail requires around 10-15 tanner sub and requires dyed sheep leather; the bronze scale mail was only recently "discovered" and it requires a 25 armorsmith with at least a 20 tanner subcraft to make them easily and requires 2 different dyed buffalo leathers. With the early lack of leather dyes for each tier combined with the high level of a subcraft to create successfully, these armors are just that much harder to make than a bronze haub, which if you wanted you could buy every ingredient to make it from a vendor.
I currently am just wearing chainmail on my 14 gladiator until around 22ish, when the Bronze Haub surpasses the Sentinel's Chainmail in effectiveness. I do admit to using a Bronze Scutum over a Bronze Hoplon/Pelta because the scutum is so much cheaper to repair since it requires only 1x Bronze square as opposed to the 1x Bronze plate for the hoplon/scutum, and I can repair it myself, which is why I am avoiding the wooden line of shields.