head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
A gritty WWII Call of Duty that introduced the Zombies mode.
Execution · Practiced Mastery
An arcade-style international soccer simulation.
Call of Duty: World at War leans Execution (Practiced Mastery); Iss3 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Twitch gunfights in fast multiplayer lobbies
Iss3
passing and shooting precision
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Human opponents reward positioning prediction
Iss3
human opponents allow light prediction
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Random lobbies, spawns, and zombie waves
Iss3
match physics randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: World at War
Perk loadouts and map control are learnable
Iss3
team tactics and formation strategy
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.