head to head
Neither is simply harder - they are hard in different places. Guilty Gear Strive demands more reads; StarCraft demands more optimization.

Execution · Grand Arena
A fast anime fighter where execution and yomi compound under pressure.

Optimization · Grand Arena
A real-time strategy classic where perfected build orders and mechanical speed decide most matches.
Guilty Gear Strive leans Execution (Grand Arena); StarCraft leans Optimization (Grand Arena).
Guilty Gear Strive leans clearly harder on execution.
Guilty Gear Strive
Tight links, RCs, and burst timing are demanding.
StarCraft
APM and micro control ceiling is huge
Guilty Gear Strive leans clearly harder on reads.
Guilty Gear Strive
Adaptive opponents bait Roman Cancels and throws.
StarCraft
scouting and predicting human opponent builds
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Guilty Gear Strive
Essentially deterministic match flow.
StarCraft
minimal hidden info beyond fog of war
StarCraft leans clearly harder on optimization.
Guilty Gear Strive
Matchup data, combo routes, and tension management.
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.