head to head
DayZ asks more than FIFA 21, and the gap is variance.

Variance · Grand Arena
Hardcore survival sandbox where other players are scarier than the zombies.

Execution · Competitive PvP
Football sim testing execution and opponent reading under a studied tactical meta.
DayZ leans Variance (Grand Arena); FIFA 21 leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
DayZ
gunfights punish slow hands severely
FIFA 21
Skill moves and finishing mechanics demand practiced hands
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
DayZ
every survivor met may lie, ambush, or befriend
FIFA 21
Outguessing a human's defensive shape and attacking patterns is central
DayZ leans clearly harder on variance.
DayZ
loot spawns and who you meet are unknowable
FIFA 21
Deflections, finishing RNG and pack luck colour outcomes
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
DayZ
map knowledge and survival routines compound
FIFA 21
Meta formations, custom tactics and squad building are studied deeply
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.