head to head
Neither is simply harder - they are hard in different places. Under Night In-Birth II Sys:Celes demands more reads; Warcraft III: Reign of Chaos demands more variance.

Reads · Grand Arena
A neutral-focused fighter where managing the GRD gauge against an adapting opponent creates a constant strategic tug-of-war.

Optimization · Grand Arena
Blizzard's hero-centric RTS where build-order theory meets surgical unit micro against humans.
Under Night In-Birth II Sys:Celes leans Reads (Grand Arena); Warcraft III: Reign of Chaos leans Optimization (Grand Arena).
Under Night In-Birth II Sys:Celes leans a little harder on execution, though the gap is small.
Under Night In-Birth II Sys:Celes
GRD-boosted combos and precise Chain Shift timing demand real execution
Warcraft III: Reign of Chaos
Micro of heroes and units decides fights
Under Night In-Birth II Sys:Celes leans clearly harder on reads.
Under Night In-Birth II Sys:Celes
GRD tug-of-war with a human opponent is persistently adaptive
Warcraft III: Reign of Chaos
Scouting and out-guessing a human opponent's tech
Warcraft III: Reign of Chaos leans clearly harder on variance.
Under Night In-Birth II Sys:Celes
No RNG; GRD state is visible information
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.
Under Night In-Birth II Sys:Celes
GRD management theory and optimal punish routing are well-documented
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.