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

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

Execution · Grand Arena
Battle royale survival blending aim, rotation planning, and heavy circle-and-loot RNG.
H1Z1 leans Execution (Grand Arena); PUBG Mobile leans Execution (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
PUBG Mobile
Touchscreen aim and recoil control set the ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
H1Z1
Outguessing human rotations and pushes
PUBG Mobile
Outguessing rotations and third-party timing of human squads
PUBG Mobile leans a little harder on variance, though the gap is small.
H1Z1
Loot spawns and gas circles randomise runs
PUBG Mobile
Circle placement, loot and drop locations dominate single matches
PUBG Mobile leans a little harder on optimization, though the gap is small.
H1Z1
Drop spots, loot routes, and zone play
PUBG Mobile
Zone rotation theory and loadout priorities are well mapped
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.