head to head
Neither is simply harder - they are hard in different places. Tekken 8 demands more execution; Warcraft III: Reign of Chaos demands more variance.

Execution · Grand Arena
A 3D fighter where movement and mixup reads decide rounds.

Optimization · Grand Arena
Blizzard's hero-centric RTS where build-order theory meets surgical unit micro against humans.
Tekken 8 leans Execution (Grand Arena); Warcraft III: Reign of Chaos leans Optimization (Grand Arena).
Tekken 8 leans clearly harder on execution.
Tekken 8
Just-frame inputs and 3D movement punish sloppy hands.
Warcraft III: Reign of Chaos
Micro of heroes and units decides fights
Tekken 8 leans clearly harder on reads.
Tekken 8
Adaptive opponents mix lows, highs, and throws.
Warcraft III: Reign of Chaos
Scouting and out-guessing a human opponent's tech
Warcraft III: Reign of Chaos leans clearly harder on variance.
Tekken 8
Negligible RNG in core matches.
Warcraft III: Reign of Chaos
Creep routes and item drops add randomness
Warcraft III: Reign of Chaos leans clearly harder on optimization.
Tekken 8
Frame data, punishes, and movelist depth.
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.