So, I've submitted a patch:
Armor balancing patch. See the wiki and forum for reasons to change armor stats.
The patch that changes C code computing damage done to armor, now does 10 times less damage to armor and bases it not on the damage that harms body, but on the damage that is blocked by the armor (the more you block, the more the armor suffers). This differentiates plasma and tachyon damage types even more and makes armor degradation slower when the armor is already damaged (and not faster, as is currently). Still, one big plasma blast should wipe half of intact Hard Nano Armor, which is the intended behaviour (next blast should wipe only about one quater of the remaining armor protection points, but the body will be harmed much more).
Previously armor was destroyed totally with one or two
alien shots. Now the game should be easier and more
reasonable. Preliminary tests show soldiers are now
able to withstand longer on the battlefies, but without
any display of armor remaining protection points in
game it's hard to tell if everything goes as I envisioned.