there is a crit table
look how much crit power roll do u need to make someone KO,
MoS giving only 10 crit power res( it not giving crit chance res) + 10 crit power res from CAmk2, most aiming shotters(including npcs) have better critical(giving 20 crit power) but look on crit table again, this marked roll is on EN, and look on stonewall script(there is not on wiki about KO res from stonewall)
if(FLAG(eff, HF_KNOCKOUT) && target.Perk[PE_STONEWALL] != 0 && Random(1, 10) <= (target.Stat[ST_ENDURANCE] - 5))
UNSETFLAG(eff, HF_KNOCKOUT);
so simple stonewall giving u a 5 EN to roll in this marked roll on picture above
so stonewall protecting ur body from KO on low crit power rolls
MoS protecting u only from eyes KO in pratice, that's why i dont recomment to any new or experience ppl, is totally useless and wasted perk if u taking it without stonewall.