I am not sure where or how you guys are picking the stats but you are way over and in some case way under what would be true: here is an Idea for you to think about:

First of 8-11 range is "average". So everyone would have a range in this area for every stat except for some major, or even minor issues.

Strength 9-10 average, anything above 18 is "Olympic level strength"; My son is a power lifter i figure he has 18/75 or so strength) and he can bench 350, dead lift 750. a soldier who is on combat arms, specifically infantry would have a strength of 15-16, being able to carry a 35 pound combat load with no fatigue. It is possible to have a low strength because of lack of fitness, but anything below say 8 would mean some type of psychical issue, i.e. congenital deformity or acquired injury.

Intelligence can directly be translated to IQ so a 13 would be an IQ of 130. and anything below an 8 being effectively illiterate and mentally deficient, with say a 6 being the intellect of a 6 year old child.

Wisdom is can be measured as a function of intelligence.There was a dragon magazine article that talked about this relationship and i do not know which one it was. But it posited that it would be impossible to have a person with say a 9 intelligence and an 18 wisdom. That said there is no reason why a "mentally deficient" character could not have a high wisdom with a low IQ score. especially if this deficiency was an acquired deficiency do to Traumatic Injury later in life.

Dexterity is a separate statistic with an 15 being "Olympic level" or "professional dancer level", again anything 8 or below would be from some type of physical impairment.

Constitution is a function of strength, you can not be solid of body and weak, it doesn't work that way. especially since constitution is a measure of "physique" PHB 1 ed page 12. Anything less than 8 would be a physical impairment, Raistlin Majere had a con of 10, I am not sure how this was considering how weak he was. But those are the stats given.

Charisma is a separate stat and the hardest to quantify, it is a measure of PERSONALITY not only looks.

Many of the above stats can be broken down into 3 areas of concentration:

Strength: Muscle mass, Endurance, and Stamina.
Intelligence: Deductive reasoning, Memory, and Learning ability.
Wisdom: Intuition, Judgment, and Willpower
Dexterity: Fine motor skills, Reflex, and Speed.
Constitution: Health, Resistance, Fitness
Charisma: Persuasion, Magnetism, and Attractiveness.

Based on this you can scale each of the three on a scale of 1 to 6 and then add them together.

So, for me:

Strength: 3, 5, 5: total 13, a little low for a soldier, but then again i did struggle with the physical aspects of the job, and i never had a first class pt test.
Intelligence: 4, 5, 5: total 14 i have an IQ of 140 =/- 5, so pretty close.
Wisdom: 5, 3, 3: total 11, I am a leadership challenge because i make bad decisions sometimes. So again pretty true.
Dexterity: 6, 5, 5: total 16; I am a Dan level martial artist so this fits, and I can shoot 90% at 800 meters, and i was at the junior Olympics as a child.
Constitution: 4, 3, 3; total 10 I am 15 pounds overweight, but not unhealthy my cholesterol is fine and I don't have any other issues.
Charisma: 4, 4, 3; total 11 I have a certain amount of magnetism in me, even though i am average looking.

These stats were acquired over a 48 year life of study of martial arts, soldering ( I was in the Army), and graduate level studies in the social sciences. And with a career in Cartography and Urban Planning. The only place i really excel is IQ and Dexterity.

My Daughter would be:

Str: 8 she is out of shape and has very little stamina because of it.
Int 16 she is highly intelligent, even more so than me.
Wis 16 she is pretty open minded and intuitive.
Dex 13 She is also a Dan level martial artist, but being sick has taken its toll.
Con 7 She was born with a CHD, and has had two heart transplants and is in heart failure now.
Cha 8 She is crabby and bitchy because of her illness, and she was never properly socialized as as a child do to hospitalizations.

High School Graduate with some college.