Ok so not knowing how Toady designed this, here's a view on chain armor from a RL blacksmith/armorer/blademaker. (15 yrs+ now)
We were also curious about how chain really worked, so we made some
medieval equivalent armor, blades, maces/hammers etc.
We did our testing with meat and poplar wood to represent bone(lets just say our steaks were REALLLY tender that night). We did this all to the best of our abilities and time allowed, and mostly just expense.
riveted chain vs. 1 handed 42" steel longsword - as expected, against slashes and draw cuts it was really good. Most solid thrusts pierced, causing large amounts of damage, possible instakills.Hacking? Well, well placed solid hacks SHEARED the mail. The rivets gave first (not surprising, weakest part) but also many links were simply cut in half, in addition to them being bent and that causing the other mail links to split. We're only going to discuss hacking then. Hacks against just thin meat (i.e guts) were, well, impressively destructive. Joints were broken, but not destroyed. Other bone areas (ribs, shoulders)were damaged and broken but viable. Against thick meat(legs, other muscled areas), definitely wounded, but in our best estimate, no instakill.
Axes 1hand, 3pounds, 7" cutting edge- Oh my dear god, the carnage. Generally only about 3" of the blade hit, increasing penetration. At best, the mail caused glancing blows. If it hit solid, it sheared and you had several inches of penetration/damage. Joints did however, not shear, mostly because they were simply destroyed by the blunt force.
Blunt mass weapons - Yeah, it was ugly. Joints and bone were simply splintered. Muscle had the links broken and driven into the wound. Guts, though, were not instakills.
Crossbows, 125 lb pull - Slightly reduced damage, but not noticeably.
Crossbow, 500(estimated) lb pull- No difference. As a matter of fact, it also went through the brick at the back of the garage, glanced off a tree, and buried itself in the ground. BTW - for the time, that was considered a hunting bow, or a light military weapon.
So then we added
gambesons, padded under armor, which would have been standard, stuffed with hair.
All damage was SIGNIFICANTLY reduced, except for crossbow, who still laughed on the way through, but at least stopped at the 16" of 4" x 4"s we hastily erected as a backstop. A lot of killing damage was then survivable, at least for the fight anyways. The hair stuffing was surprisingly tough.
Ok so whats the point of all this?
1 - Tensile and shear strength of the metal used for the mail was really really important.
2 - Gambesons were absolutely vital, for reasons beyond comfort.
3 - Real medieval chain was STILL a hell of a lot better than ours. They used a tighter weave density, with thicker wire. We believe this would account for the difference in thrusting damage data. Real chain was simply better against it.
My best guess as a blacksmith with an engineering degree? All things being equal, the density shouldn't matter, well except to make it even heavier to wear. (25-50lbs depending on weave density and wire thickness) The amount of deflection is at best 2" - 3" around a 4" circle (approx). Reducing the area of contact would make density have even less to do with it, and dramatically increase the importance of yield, fracture, and elasticity. Some quick napkin math says a 4" circle would be about 1.3 lbs of steel, and 1.5 lbs of copper, and no that takes none of variables into account, just a quick show of approximates.
Now - the biggest question is how realistic is Toady's programming? His simulations are amazing, but he would still go by guesses and assumptions for how combat works, and how weapons work. Hell, even the scholars still just go by guesses and assumptions.
So, in other words, going by raws AND an understanding of how it really works, adamantine chain should be the best way to go, by a huge margin, so why isn't it?