head to head
Middle-earth: Shadow of War 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
Nemesis-system sequel that adds orc army management and fortress sieges.
Grand Theft Auto V leans Execution (Practiced Mastery); Middle-earth: Shadow of War leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Middle-earth: Shadow of War
Same counter-heavy combat as its predecessor
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.
Middle-earth: Shadow of War
Nemesis system mimics adaptation but follows knowable rules
Middle-earth: Shadow of War leans clearly harder on variance.
Grand Theft Auto V
Some mission and lobby randomness.
Middle-earth: Shadow of War
Random orc traits, betrayals, and fortress compositions
Middle-earth: Shadow of War leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Middle-earth: Shadow of War
Army building and siege planning layer on top
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.