head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is optimization, and it is a single point.

Optimization · Practiced Mastery
Open-ended stealth sandbox built on base-building and adaptive AI.

Optimization · Pure Optimization
Sandbox medieval sim spanning personal swordplay up to running a kingdom's economy.
Metal Gear Solid V: The Phantom Pain leans Optimization (Practiced Mastery); Mount & Blade II: Bannerlord leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Solid V: The Phantom Pain
Stealth and shooting inputs both matter.
Mount & Blade II: Bannerlord
Directional melee blocking and mounted combat
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Solid V: The Phantom Pain
Guards adapt loadouts across missions, light modeling.
Mount & Blade II: Bannerlord
Multiplayer duels add some human prediction
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Solid V: The Phantom Pain
Patrols, weather, supply drops randomize runs.
Mount & Blade II: Bannerlord
Procedural campaign politics and battles
Mount & Blade II: Bannerlord leans a little harder on optimization, though the gap is small.
Metal Gear Solid V: The Phantom Pain
Mother Base, loadouts, fulton economy deeply solvable.
Mount & Blade II: Bannerlord
Economy, army composition, and kingdom management dominate
A matching score does not mean a matching test. Two games can both sit at 10 on execution and demand completely different things of you - which is why the reasoning above matters more than the number beside it.