head to head
Mount & Blade asks more than Grand Theft Auto V, and the gap is optimization.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Optimization · Practiced Mastery
Sandbox warfare testing directional combat skill atop an optimisable army and trade economy.
Grand Theft Auto V leans Execution (Practiced Mastery); Mount & Blade leans Optimization (Practiced Mastery).
Mount & Blade leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Mount & Blade
Directional blocking and couched-lance timing demand real skill
Grand Theft Auto V leans a little harder on reads, though the gap is small.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Mount & Blade
AI lords and battle tactics are mappable scripts
Mount & Blade leans a little harder on variance, though the gap is small.
Grand Theft Auto V
Some mission and lobby randomness.
Mount & Blade
World events, prices and tournaments shuffle each campaign
Mount & Blade leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Mount & Blade
Army composition, trade economy and fief management drive conquest
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.