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
Base-building strategy game about optimizing upgrade economy and raid compositions.

Optimization · Pure Optimization
Map-painting grand strategy ruled by mana and idea optimization.
Clash of Clans leans Optimization (Pure Optimization); Europa Universalis IV leans Optimization (Pure Optimization).
Europa Universalis IV leans a little harder on execution, though the gap is small.
Clash of Clans
Troop drop placement is forgiving
Europa Universalis IV
pausable, no twitch
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Clash of Clans
Base layouts anticipate human attackers' habits
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.
Clash of Clans
Matchmaking and unseen traps add uncertainty
Europa Universalis IV
events, mission paths
Europa Universalis IV leans a little harder on optimization, though the gap is small.
Clash of Clans
Army comps, upgrade paths, and attack routing
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.