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

Execution · Practiced Mastery
Co-op-focused action sequel hurling Titus against Tyranid swarms with parry-heavy melee combat.

Execution · Pure Mechanics
A brisk action RPG where flash-guard reflexes and party-swap execution carry fights through scripted raid and field encounters.
Warhammer 40,000: Space Marine 2 leans Execution (Practiced Mastery); Ys VIII: Lacrimosa of DANA leans Execution (Pure Mechanics).
Ys VIII: Lacrimosa of DANA leans a little harder on execution, though the gap is small.
Warhammer 40,000: Space Marine 2
Parry, dodge and gun-strike timing against swarms
Ys VIII: Lacrimosa of DANA
Flash-guard timing and fast party-swap combos reward tight inputs
Warhammer 40,000: Space Marine 2 leans a little harder on reads, though the gap is small.
Warhammer 40,000: Space Marine 2
PvP Eternal War adds some human prediction
Ys VIII: Lacrimosa of DANA
Enemies are fully scripted; Raid defence waves follow fixed patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Warhammer 40,000: Space Marine 2
Tyranid swarm spawns vary run to run
Ys VIII: Lacrimosa of DANA
Loot from fishing and gathering adds light RNG to item acquisition
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Warhammer 40,000: Space Marine 2
Class builds and perk loadouts reward planning
Ys VIII: Lacrimosa of DANA
Element weakness matching and party comp planning reward systematic play
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.