head to head
Neither is simply harder - they are hard in different places. Call of Duty: Warzone demands more variance; StarCraft demands more optimization.

Execution · Grand Arena
Battle royale built on COD's tight gunplay.

Optimization · Grand Arena
A real-time strategy classic where perfected build orders and mechanical speed decide most matches.
Call of Duty: Warzone leans Execution (Grand Arena); StarCraft leans Optimization (Grand Arena).
Call of Duty: Warzone leans clearly harder on execution.
Call of Duty: Warzone
Long-range gunfights reward perfect aim
StarCraft
APM and micro control ceiling is huge
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Warzone
Rotations and third-party reads decide fights
StarCraft
scouting and predicting human opponent builds
Call of Duty: Warzone leans clearly harder on variance.
Call of Duty: Warzone
Drops, loot, circles inject real RNG
StarCraft
minimal hidden info beyond fog of war
StarCraft leans clearly harder on optimization.
Call of Duty: Warzone
Meta loadouts and rotations heavily solved
StarCraft
build orders and economy are near-solvable
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.