head to head
The Elder Scrolls V: Skyrim asks more than Pokémon Diamond Version, and the gap is execution.

Optimization · Pure Optimization
Solvable team-building progression through Sinnoh's fixed trainers.

Optimization · Pure Optimization
An open-world RPG mostly about discovering and stacking exploitable progression systems.
Pokémon Diamond Version leans Optimization (Pure Optimization); The Elder Scrolls V: Skyrim leans Optimization (Pure Optimization).
The Elder Scrolls V: Skyrim leans clearly harder on execution.
Pokémon Diamond Version
Menu battles need no dexterity
The Elder Scrolls V: Skyrim
Combat is forgiving; aim and timing rarely punish you.
Pokémon Diamond Version leans a little harder on reads, though the gap is small.
Pokémon Diamond Version
Scripted trainers never adapt; online battles are optional
The Elder Scrolls V: Skyrim
Enemy AI is scripted and exploitable; not adaptive.
Pokémon Diamond Version leans a little harder on variance, though the gap is small.
Pokémon Diamond Version
Encounter and crit rolls are bounded, mappable randomness
The Elder Scrolls V: Skyrim
Loot tables and leveled lists inject mild randomness.
Pokémon Diamond Version leans a little harder on optimization, though the gap is small.
Pokémon Diamond Version
Physical-special split deepens solvable team building
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.