head to head
Neither is simply harder - they are hard in different places. H1Z1 demands more variance; Warcraft III: Reign of Chaos demands more optimization.

Execution · Grand Arena
Early battle royale where scavenged loot and shrinking gas decide 150-player brawls.

Optimization · Grand Arena
Blizzard's hero-centric RTS where build-order theory meets surgical unit micro against humans.
H1Z1 leans Execution (Grand Arena); Warcraft III: Reign of Chaos leans Optimization (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
H1Z1
Gunfights and vehicle control decide duels
Warcraft III: Reign of Chaos
Micro of heroes and units decides fights
Warcraft III: Reign of Chaos leans a little harder on reads, though the gap is small.
H1Z1
Outguessing human rotations and pushes
Warcraft III: Reign of Chaos
Scouting and out-guessing a human opponent's tech
H1Z1 leans clearly harder on variance.
H1Z1
Loot spawns and gas circles randomise runs
Warcraft III: Reign of Chaos
Creep routes and item drops add randomness
Warcraft III: Reign of Chaos leans clearly harder on optimization.
H1Z1
Drop spots, loot routes, and zone play
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.