Sorry for the looooong post but I'm kind of ancient armours/weapons maniac.
I quote from Core Rules 2e, page. 178:
"...the damage reduction provided by the armour is halved (rounded down) for that blow..."
DR 1 divided by two means 0.5, rounded down to 0.
I do not see why a steel cap should protect you more than that.
The Barbaric warrior tables are interesting, they remind me of old good AD&D2 Dark Sun tables for piecemeal armours....but I'm not so sure that table you are refering to is good, and I spotted many errors!
It makes differences between Iron and Steel which is interesting, ... but they do not care wether steel is used for chain mail, plate or scale!
And the variance between Mail, Plate or Scale is kept as important in Conan Core Rules armours!
While Conan Core rules never mentions bone armours...
Furthermore, that table says "brass"!!!
That's crazy! I think the author meant "bronze".
And, if so, I'm not so sure a "bronze" torso armor should protect less than a "iron" armor (but maybe less than a steel one).
Bronze was widely used in Greco-Roman armors even if they knew some kind of steel, and bronze is not less expensive than iron!
Bronze is heavier than iron and steel (so why the author give more sorcery penalty to Steel and why Steel have the same Dex max bonus of Bronze?)
WHY CONAN ALWAYS WEARS HELM & Bracers?
The reasons is that helms and bracers are "cool" for Conan artists!
I suppose the whole thing came from Frazetta's work and 1970s' marvel comics.
The Conan approach to armours in original Conan stories is completely different.
I suggest you to re-read REH and you'll notice that Conan always tries to wear the best possible armour.
You can find a list even in Conan rpg 2e pag. 394-5:
- Mail armour+helm in Frost giant Daughter
- Full armour+helm in Queen of the Black Coast
- Mail armour in Black Colossus
- Off course he wears always the best armours (usually Chain Mail and unless he is prisoner) in all the 3 stories as a King (Phoenix on the sword, Scarlet Citadel, Hour of the Dragon).
When he does not wear decent armour there is always a reason why:
- He is crucified in A Witch shall be born (but later he got mail armour)
- He is at the head of a savage tribe of blackmen (so I guess, very warm, humid climate, bad for metal armours) in The Vale of Lost Women
- he is a poor fugitive wandering in the swamps (so maybe he has thrown armor away to not drown) in Shadows in the moolight.
- He starts as a poor wanderer or thief with no money (Tower of the Elephant, God in the Bowl, Rogues in the House, Shadows in Zamboula).
Now, let's forget Frazetta and let consider Ancient warfare.
It's not the bracers & helm to make a difference...but the shield!
Small Bracers are useless, while helm and greaves should be the decent compendium to a shield (to protect the upper and lower areas not covered by the shield).
But if you do not have shield....it's not the helm to make the difference!
That's why all the warriors who had the economic possibility in a series of ancient societies (from Etruscans to Vikings) looked for torso protection after they got the shield (and unless they were crazy alcoholic berserkers...).
There's a reason why most Roman gladiators (excepting the Retiarius and Dimachaerus) had helms and shields but rarely had torso protection...the shield is their main defence, and if they were not skillfull in using it, they had to die in horrible ways to entertain the public.
All of the opposite for Roman legionaries or Greek Hoplites.
even if they had large shields they looked for torso protection, since helm and greaves were not enough!