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

Optimization · Pure Optimization
A tower defense game with offense, sending units while defending your base.

Optimization · Pure Optimization
Map-painting grand strategy ruled by mana and idea optimization.
Defenders of Ardania leans Optimization (Pure Optimization); Europa Universalis IV leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Defenders of Ardania
Placing towers and units needs no physical speed
Europa Universalis IV
pausable, no twitch
Defenders of Ardania leans a little harder on reads, though the gap is small.
Defenders of Ardania
Multiplayer attack-defense adds genuine opponent prediction
Europa Universalis IV
AI mostly scripted, some MP
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Defenders of Ardania
Spell outcomes and unit waves add some randomness
Europa Universalis IV
events, mission paths
Europa Universalis IV leans a little harder on optimization, though the gap is small.
Defenders of Ardania
Tower placement, unit waves and spell timing are solvable
Europa Universalis IV
idea groups, economy, mana spending
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.