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

Optimization · Practiced Mastery
A long Viking RPG carried by exploration and gear progression.

Optimization · Practiced Mastery
A real-time RPG carried by ascension-grid routing and magic crafting.
Assassin's Creed Valhalla leans Optimization (Practiced Mastery); Final Fantasy XV leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Assassin's Creed Valhalla
Combat timing matters but forgiving.
Final Fantasy XV
Real-time combat, modest input demand
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Assassin's Creed Valhalla
Enemies scripted and predictable.
Final Fantasy XV
Scripted enemies
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Assassin's Creed Valhalla
Loot rolls and raid encounters vary mildly.
Final Fantasy XV
Loot and ascension variance
Final Fantasy XV leans a little harder on optimization, though the gap is small.
Assassin's Creed Valhalla
Skill tree, gear, raid routing solvable.
Final Fantasy XV
Ascension grid, magic crafting, party planning
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.