head to head
Neither is simply harder - they are hard in different places. Anno 2070 demands more optimization; The Elder Scrolls V: Skyrim demands more execution.

Optimization · Pure Optimization
A futuristic city-builder where eco and industrial factions race to settle a flooded Earth.

Optimization · Pure Optimization
An open-world RPG mostly about discovering and stacking exploitable progression systems.
Anno 2070 leans Optimization (Pure Optimization); The Elder Scrolls V: Skyrim leans Optimization (Pure Optimization).
The Elder Scrolls V: Skyrim leans clearly harder on execution.
Anno 2070
Building and routing, no reflexes
The Elder Scrolls V: Skyrim
Combat is forgiving; aim and timing rarely punish you.
Anno 2070 leans a little harder on reads, though the gap is small.
Anno 2070
Faction AI is scripted
The Elder Scrolls V: Skyrim
Enemy AI is scripted and exploitable; not adaptive.
The Elder Scrolls V: Skyrim leans a little harder on variance, though the gap is small.
Anno 2070
Map generation varies resources slightly
The Elder Scrolls V: Skyrim
Loot tables and leveled lists inject mild randomness.
Anno 2070 leans clearly harder on optimization.
Anno 2070
Eco-versus-industry chains reward exact balancing
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.