head to head
Neither is simply harder - they are hard in different places. StarCraft demands more optimization; Street Fighter V demands more reads.

Optimization · Grand Arena
A real-time strategy classic where perfected build orders and mechanical speed decide most matches.

Reads · Grand Arena
A reads-heavy neutral game where V-System decisions and opponent modelling decide bouts.
StarCraft leans Optimization (Grand Arena); Street Fighter V leans Reads (Grand Arena).
Street Fighter V leans a little harder on execution, though the gap is small.
StarCraft
APM and micro control ceiling is huge
Street Fighter V
V-Trigger combos and meaty setups require solid execution
Street Fighter V leans clearly harder on reads.
StarCraft
scouting and predicting human opponent builds
Street Fighter V
V-System neutral game heavily rewards opponent habit exploitation
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
StarCraft
minimal hidden info beyond fog of war
Street Fighter V
No RNG; match flow is entirely player-driven
StarCraft leans clearly harder on optimization.
StarCraft
build orders and economy are near-solvable
Street Fighter V
Season-by-season tier lists and V-Skill routing reward study
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.