head to head
Neither is simply harder - they are hard in different places. Fire Emblem: Three Houses demands more optimization; The Elder Scrolls V: Skyrim demands more execution.

Optimization · Pure Optimization
A tactical RPG solved through long-horizon build and class planning.

Optimization · Pure Optimization
An open-world RPG mostly about discovering and stacking exploitable progression systems.
Fire Emblem: Three Houses leans Optimization (Pure Optimization); The Elder Scrolls V: Skyrim leans Optimization (Pure Optimization).
The Elder Scrolls V: Skyrim leans clearly harder on execution.
Fire Emblem: Three Houses
Menu-driven, no mechanical bar
The Elder Scrolls V: Skyrim
Combat is forgiving; aim and timing rarely punish you.
Fire Emblem: Three Houses leans a little harder on reads, though the gap is small.
Fire Emblem: Three Houses
AI follows fixed aggression rules
The Elder Scrolls V: Skyrim
Enemy AI is scripted and exploitable; not adaptive.
Fire Emblem: Three Houses leans a little harder on variance, though the gap is small.
Fire Emblem: Three Houses
Hit rates and crit RNG affect runs
The Elder Scrolls V: Skyrim
Loot tables and leveled lists inject mild randomness.
Fire Emblem: Three Houses leans clearly harder on optimization.
Fire Emblem: Three Houses
Class routing and build planning dominates
The Elder Scrolls V: Skyrim
Skill stacking, enchant loops, and exploits are deeply 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.