Exp rate always looks at your base level, but there are some skills that can get bonuses or penalties from stronger opponent logic. Ranging from x0.1 to x6 exp, depending on if you're stronger or weaker than your opponent.

It depends on the skill though.

Dexterity is affected by stronger opponent logic, but it doesn't compare itself (it unusually compares your melee attack/melee defense to the opponent's opposite skill, or Martial Arts in the case of unarmed combat), so penalties and bonuses to it are irrelevant. Bonuses are better, because faster attacks means more hits in less time, meaning faster training.

Strength is completely unaffected by this system though. Your strength modifiers will not affect your growth, beyond making it easier or harder to be over-encumbered or changing what counts as a "heavy" weapon.

While Melee Attack is fully part of this system, and debuffing it can have significant bonuses on your exp rate for itself.

The wiki page for stronger opponent logic has more detailed info on all this.
https://kenshi.fandom.com/wiki/Stronger_Opponent_Logic

Originally posted by Shidan:

Exp rate always looks at your base level, but there are some skills that can get bonuses or penalties from stronger opponent logic. Ranging from x0.1 to x6 exp, depending on if you're stronger or weaker than your opponent.

It depends on the skill though.

Dexterity is affected by stronger opponent logic, but it doesn't compare itself (it unusually compares your melee attack/melee defense to the opponent's opposite skill, or Martial Arts in the case of unarmed combat), so penalties and bonuses to it are irrelevant. Bonuses are better, because faster attacks means more hits in less time, meaning faster training.

Strength is completely unaffected by this system though. Your strength modifiers will not affect your growth, beyond making it easier or harder to be over-encumbered or changing what counts as a "heavy" weapon.

While Melee Attack is fully part of this system, and debuffing it can have significant bonuses on your exp rate for itself.

The wiki page for stronger opponent logic has more detailed info on all this.
https://kenshi.fandom.com/wiki/Stronger_Opponent_Logic

Yea I had a look at that page, but it left some things unanswered / I didn't fully understand what it meant in the bigger picture, hench the above questions.

So if I'm looking to level a character without cheesing like using prisoners and just have a rescue / medical character nearby on stealth, how would I best approach training for combat?

Because people said that armor with many negatives is good because it lowers the stat, therefor making it easier to train up, but if it compares to the base stat that wouldn't be true?

I'll additionally ask some more precise questions (I'd still appreciate if you could could further explain/answer the above though):

1: Would wearing a large backpack vs a small ninja backpack help combat training and stealth/dodge training? It has a -10 MA/MD malus so that would be making me worse at combat in short term, but faster training right due to being more equal / lower than opponents skill?

1.1: Would training vs dummies be faster if malus stats to melee attack are applied or does that only affect base stats?

2: Would Stealth and Dodge also train faster due to the 0.25x multiplier to those stats on the large backpack?

3: If the answer to question 2 is 'No', are x.xx multipliers always a bad thing then? or are there benefits to having reduced Dexterity, Dodge, Stealth or Athletics etc?

4: If the answer to 3 is 'Yes always bad', the only thing to look out for then to improve combat training is minus stats to melee attack and melee defense correct, while trying to keep dexterity as high as possible?

5: Are racial multipliers multipliers to xp gain or to base stat? I always assumed it was to xp gain as that's what most race wiki pages say (xp rate), but I was reading the wiki on Cat-Lon and it says "Due to Cat-Lon's race bonus he has an impressive 120 Heavy Weapon Skill." implying that the race bonus / debuff is a stat modifier, not an exp gain modifier?

Actually, upon reading the Stronger Opponent Logic page again, the last paragraph / section seems to answer my question, I had to re-read it 4 times to fully graps/understand it, but basically.

For most calculations base stats are taking into account.
The exceptions are:

Armour Modifiers
Backpack penalties
Encumbrance penalties (though the penalties are only applied to Martial Arts and Dodge)
Indoor bonuses/penalties
Injuries (though the penalties themselves are only applied to Dodge)
Weather penalties
Weapon modifiers (though obviously only weapon users get the modifiers themselves)

So then it makes sense why people say just gear up in stuff that gives you debuffs.
But it also means I don't need to worry about the stats provided by limbs, as those aren't taking into account for xp calculation.