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.

Optimization · Pure Optimization
A deep dual-class build system where optimising passive constellations and resist thresholds is the core challenge.

Optimization · Pure Optimization
A blade-driven JRPG won by chain-attack routing and combo optimization.
Grim Dawn leans Optimization (Pure Optimization); Xenoblade Chronicles 2 leans Optimization (Pure Optimization).
Grim Dawn leans a little harder on execution, though the gap is small.
Grim Dawn
Boss fights and Crucible have limited twitch demand
Xenoblade Chronicles 2
Auto-attack with art-timing inputs
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Grim Dawn
Solo and co-op PvE throughout; no adaptive opponent
Xenoblade Chronicles 2
Scripted enemies
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grim Dawn
Drop RNG and component rolls add moderate hidden information
Xenoblade Chronicles 2
Blade gacha and crit rolls
Grim Dawn leans a little harder on optimization, though the gap is small.
Grim Dawn
Dual-class mastery system and devotion tree are extensively solvable
Xenoblade Chronicles 2
Blade combos and chain attack routing central
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.