head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Reads · Grand Arena
Cold-War base-builder where tight production queues and superweapon races define competitive play.

Optimization · Grand Arena
Blizzard's hero-centric RTS where build-order theory meets surgical unit micro against humans.
Command & Conquer: Red Alert 2 leans Reads (Grand Arena); Warcraft III: Reign of Chaos leans Optimization (Grand Arena).
Warcraft III: Reign of Chaos leans a little harder on execution, though the gap is small.
Command & Conquer: Red Alert 2
Superweapon timing and unit grouping require practiced multitasking
Warcraft III: Reign of Chaos
Micro of heroes and units decides fights
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Command & Conquer: Red Alert 2
Opponent faction and rush timing must be scouted and predicted
Warcraft III: Reign of Chaos
Scouting and out-guessing a human opponent's tech
Warcraft III: Reign of Chaos leans a little harder on variance, though the gap is small.
Command & Conquer: Red Alert 2
Map layout is fixed; very little hidden RNG in unit behavior
Warcraft III: Reign of Chaos
Creep routes and item drops add randomness
Warcraft III: Reign of Chaos leans a little harder on optimization, though the gap is small.
Command & Conquer: Red Alert 2
Build queues and power grid management are highly optimizable
Warcraft III: Reign of Chaos
Build orders, creeping routes, and matchup theory run deep
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.