head to head
Warcraft III: Reign of Chaos asks more than Overwatch, and the gap is optimization.

Execution · Grand Arena
Team hero shooter blending FPS mechanics with ability economy mind games.

Optimization · Grand Arena
Blizzard's hero-centric RTS where build-order theory meets surgical unit micro against humans.
Overwatch leans Execution (Grand Arena); Warcraft III: Reign of Chaos leans Optimization (Grand Arena).
Overwatch leans a little harder on execution, though the gap is small.
Overwatch
Hero aim, movement, and ability timing
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.
Overwatch
Ult tracking, flanks, and baiting human teams
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.
Overwatch
Minor spread and matchmaking noise
Warcraft III: Reign of Chaos
Creep routes and item drops add randomness
Warcraft III: Reign of Chaos leans clearly harder on optimization.
Overwatch
Team comps, ult economy, and positioning theory
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.