Tests I have seen where someone shot arrows at mail are pretty much universally poorly done. Do not be misled by some guys on TV shooting a streched out sheet of mild steel mail made from far too wide and thin rings attached to a wooden board.
Mail varied in quality greatly, but none of it was 'useless'. It was a very substantial investement, hugely laborious to make, yet used for over a thousand years in numerous places in the world.
Well made mail stopped arrows dead in their tracks. Plenty stories exist of crusaders walking around as arrow pin cushions. They lost a tabbard and probably got bruised black and blue, but were otherwise unharmed.
A few other things to remember are that mail was worn over a layer of very thick padding which cushioned blows and would render a minor penetration harmless. Mail when worn also does not stretch out fully but, if woven and worn correctly, will have slack left in the fabric and closely fall around the body.
To put it shortly, mail was pretty good stuff. Not as protective as plate armor, but still pretty good and much, much better than then the padded stuff the poorest saps on the battlefield wore (though even those were not as bad as you might think). Those guys were the ones the archers aimed for first.
Ahem, rant aside, you can make the various weaves by making a seperate armor with a higher coverage value. Armor thickness is Coverage*Layer size*1.25(UPSTEP+LBSTEP+UBSTEP), so simply increase the resulting thickness and material cost for more luxurious weaves. That way you can still make the various mail types from different metals.
As an optional you can also add padded armor, your free to grab the ones from my mod if you want.