Wirecutters and the like pierce all armor

[somepotato]

an item so plentiful shouldn't pierce any armor so easily IMO. And it shouldn't cause as much bloodloss as it does either

Improvised weapons are the bread and butter of SS13's combat, though.

Wirecutters aren't improvised, they're fabricated from any of the many general fabricators and nearly all of the toolboxes that aren't emergency ones.