head to head
DayZ asks more than Sea of Thieves, and the gap is variance.

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

Reads · Competitive PvP
Open-world pirate game with PvPvE ship combat.
DayZ leans Variance (Grand Arena); Sea of Thieves leans Reads (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
Sea of Thieves
Ship sailing and naval gunnery require hands
Sea of Thieves leans a little harder on reads, though the gap is small.
DayZ
every survivor met may lie, ambush, or befriend
Sea of Thieves
PvP ship fights are pure mind games
DayZ leans clearly harder on variance.
DayZ
loot spawns and who you meet are unknowable
Sea of Thieves
Server encounters, weather, loot vary
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
Sea of Thieves
Routes, loadouts, ship setups solvable
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.