head to head
Neither is simply harder - they are hard in different places. Empire Earth demands more variance; StarCraft demands more execution.

Optimization · Mind & Math
14-epoch RTS where economic scaling, epoch-rush timing, and civilization counter-picks span stone age to future war.

Optimization · Grand Arena
A real-time strategy classic where perfected build orders and mechanical speed decide most matches.
Empire Earth leans Optimization (Mind & Math); StarCraft leans Optimization (Grand Arena).
StarCraft leans clearly harder on execution.
Empire Earth
Epoch-spanning army micro and hero management need consistent attention
StarCraft
APM and micro control ceiling is huge
Empire Earth leans a little harder on reads, though the gap is small.
Empire Earth
Opponent epoch rush and civilization bonuses must be predicted
StarCraft
scouting and predicting human opponent builds
Empire Earth leans clearly harder on variance.
Empire Earth
Map resource distribution adds uncertainty at start; converges quickly
StarCraft
minimal hidden info beyond fog of war
StarCraft leans a little harder on optimization, though the gap is small.
Empire Earth
Epoch advancement timing and citizen allocation are near-optimally solvable
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.