My initial thread on damage had many problems and hopefully these revisions fixes some of them. Instead of the overly complex size damage table, instead a simpler table of weapon types, associated damage, then a size modifier is applied:
Damage | example weapon
1d3 fists
1d6-1 clubs, daggers
1d3+1 short swords
1d6 long sword
2d3 great club
1d6+1 great sword
Sizes A | B
Colossal -6 | 6
Gargantuan -4 | 4
Huge -2 | 3
Large -1 | 2
Medium 0 | 1
Small 1 | 0
Tiny 2 | -1
Diminutive 3 | -2
Fine 4 | -4
Minuscule 6 | -6
A: stealth, to hit, ac
B: athletics, damage, toughness
applying damage
when damage is to be reduced below 1, instead for every -1, reduce it by 1/2 so
1 - 1 = 1/2
1 - 2 = 1/4
1 - 3 = 1/8
and so on
If fractional damage adds up to at least 1/1 apply it normally, do not carry over any faction to the next wound. Otherwise fractional damage can be waived as moot if they are ruled insignificant or tracked normally. A simple rule of thumb could be to ignore any wounds 1/16 or smaller, but apply any riders such damage may have such as poison.
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Hit locations (demi-human) (2d6)
2 eye
3 nose
4 finger
5 hand
6 arm
7 torso
8 leg
9 foot
10 toe
11 ear
12 neck
Carry Capacity Chart (Medium Sized Creature)

Carry Capacity Chart (Size Multiple)

Quadrupedes gain an additional 2x (Large Quadrupedes would have a total 8x multiplier). Creatures with a similar advantage may also benefit as determined by the GM.
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Example stat blocks, these are about as basic as I can get and are very likely to be revised later on, but mostly these exist to begin testing the coherence of the system
Medium Demihuman, Commoner
AC 10, Toughness 1
STR 0, DEX 0, SPR 0, MND 0
Speed 5m
Attack, Club +0 hit, damage 1d6
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Small Demihuman, Commoner
AC 11, Toughness 0
STR 0, DEX 0, SPR 0, MND 0
Speed 4m
Attack, Club +1 hit, damage 1d6-1
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Medium Demihuman, Town Guard
AC 12, Toughness 1, Resist Slashing 1
STR 1, DEX 0, SPR 0, MND 0
Speed 5m, Skills, Athletics 1(+1), Perception 1(+1)
Attack, Longsword +1 hit, damage 1d6+2
Equipment, Leather Armor
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Tiny cat, House
AC 14, Toughness 0, Resist Bludgeoning 1
STR 0, DEX 2, SPR 1, MND -3
Speed 7m, Skills, Athletics 1(+2), Stealth 1(+3), Perception 1(+1)
Attack, Claw +4 hit, damage 1d3-1
Bite +4 hit, damage 1d3
Rake (Ex), +4 hit, damage 1d6-2. Whenever a house cat hits the same creature with a claw twice on its turn, it may immediately perform a rake with its hind legs.
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Diminutive Rat
AC 13, Toughness -2
STR -1, DEX 1, SPR 0, MND -3
Speed 6m, Climb 3m (13, +3), Skills, Stealth 1(+2)
Attack, Bite +4 hit, damage 1d6-4
Optional
Disease (Ex), Varies (see diseases). On successfully dealing bite damage the target must make a STR Save vs DC 8 or be affiliated with the disease.
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Large Cat, Tiger
AC 11, Toughness +4
STR 3, DEX 2, SPR 2, MND -3; CB+1
Speed 9m, Skills, Athletics 1(+5), Stealth 1(+2), Perception 1(+3)
Attack, Claw +3 hit, damage 1d3+4
Bite +3 hit, 2d3+3
Rake (Ex), +3 hit, damage 1d6+3. Whenever a tiger hits the same creature with a claw twice on its turn, it may immediately perform a rake with its hind legs.
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So as an example, if a rat bit a medium sized demihuman, it would deal 1d6-4 and be applied against toughness 1 (so it would effectively be 1d6-5, or the range of -4 to 1 wound, translating the negatives into fractions gives the range of 1/64, 1/16, 1/8, 1/4, 1/2, 1, applying the rule of thumb, 1/3 of the time the rat would deal no effective damage, but otherwise deal 1/8, 1/4, 1/2, or 1 wound (out of a total of 10 wounds).