Primary Attributes for RPGs

[Man_Over_Game]

On the make-sense side, intuitively, this is a very impressive spread. It does a really good job at describing one's most fundamental traits. (very original with the Charisma-Leadership split - makes a lot of sense)

On the other, When one comes up with a new proposal for ability scores, one should ask himself/herself:
1. Functionality: How does each ability score affect various aspects of the game? (will bring a lot of mechanical changes)
2. Equality: Are they roughly equal in game functionality?
3. Adaptability: Does the new spread do such a better job than the traditional six to merit the effort that every player would require to re-learn how to work with them instead?
I played around quite a bit with redefinition of abilities and never came across a proposal (my own or others') that at the bottom line would justify the redefinition.
Because ability scores are such a fundamental part of the game mechanics, it's impossible to change them and still call the game D&D.
To this day, the traditional six is the best implementation of ability scores that I know of.

Great questions, I'll try to answer each one in kind:

1. Each major attribute has things that they're inherently good at. Physical would make you, the character, the entity, an obstacle on the battlefield. Mental would generally reflect your ability to address weaknesses, either through magical attacks or preventing weakness yourself, and Social would be working off of people's strengths, either improving an ally's ability to attack or by causing the enemy brute to be distacted and miff his giant swing.
2. Ideally, they'd be equal in value, but each with their own different uses. Being a high Physical, high Mental character would have a knack for seeing an enemy's weakness, and having ways of abusing it. On the other hand, a High Physical, High Social character can stay calm under pressure and encourage nearby allies to improve their morale.
3. I definitely think so. Oldschool DnD used 3 or so defenses (as does my example), and even current DnD has a lot of redundancy that doesn't make a lot of sense. What's the canonical difference between a 5e (Cleric 1, Fighter 1) character and a (Paladin 2) character? That the Cleric lost their faith for one level? Additionally, DnD Clerics, the people who heal and defend the weak, have a generally low Charisma score, and have less incentive to interact with common folk than the Warlock, which directly contradicts what most Cleric players actually want to do: Help People.

My intent was to create no redundancy and no mistakes as to what you actually want your character to do. No longer will you have to choose between being burly and smart, not when there's a whole suite of spells that scale off of your Physical Force and Mental Force ("Earthbending"-esc abilities). You want to be a Sherlock Holmes type with high Mental Force+Finesse and high Social Finesse, don't worry, we have a number of abilities that are aimed explicitly for that. You pick and choose what actions suit your characters when you level up, and you just have a short list of actions that your character can do doing their turn. Complex and versatile level up system that becomes simple in actual gameplay. Since the prerequisites for actions are based on a sum, you can still have some of the aforementioned "earthbending" abilities if you only have a high Mental Force stat, but you may be limited in how far you can go in that suite (only getting the first few abilities).

[Edit: Whoops, sorry, didn't mean to go off on a tangent]