in addition you will have stats/effects the sheet can’t list or doesn’t sum up, like % absorb, flat absorb, offensive debuffs granting defence like fumble/impair, but is part of your overall defensive order:
% total damage reduction
Fumbles/Impaired Aim
DA evasion
Evasion/Deflect
Low OA damage penalty
Block
Racial Reduction
Resistances
Armor
Limited Absorb (i.e. Crab)
% absorb
Flat absorb (i.e Ascension)
Health
if your armour rating sucks you will take more dmg against nemesis with physical attack, or if you don’t have phys res or other mitigation to alleviate it
if your DA is low enough to be terribly crit you will take extra dmg against nemesis with bonus crit dmg
etc etc basic dmg attack defence interactions
If a nemesis has a special move you need to pay attention to, Benji stab or bomb, or Grava Nulli balls, and you don’t pay attention to that your defences need to be potentially massively higher than if paid attention to
ex
here is me, lvl 47, killing Kubra on Veteran, in a dangerous domain mutator area, because silly as i was i applied a Warrant way way early 
Valde at 56 (different char)
could have sworn i had shots of Mossi and Grava/Benji similarly at low(er) level on Vet, but i guess i forgot to hit the button on those
looks like Grava corpse?
*edit, point is i’m not trying to “flex” or “git gud”, but showing that yes we have the means to even deal with them early game.
I’m not going to pretend that i’m a new player/don’t have thousands of hours play experience to lean back on, but not like my chars are doing much of anything out of the ordinary in terms of build or itemization either. I just have that experience to level/build char during levelling, similarly strong, as if a beginner following a guide or such/with extra pointers.
And when that awareness or experience or pointers are there, it’s more than doable to deal with Nemesis, even relatively early game, because the game/devs isn’t trying to screw us over giving us an impossible or "end kit"only scaling boss encounter - those would be the Superbosses, like a certain surprise altar they left us 
Basic stat attendance actually goes a decent long way in GD, ie you can relatively “just” out-stat your enemy