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
Sequencing unit development and tactical fights through a solvable turn-based campaign.
Clash of Clans leans Optimization (Pure Optimization); Disciples III: Reincarnation leans Optimization (Pure Optimization).
Clash of Clans leans a little harder on execution, though the gap is small.
Clash of Clans
Troop drop placement is forgiving
Disciples III: Reincarnation
Turn-based combat has no physical component
Clash of Clans leans a little harder on reads, though the gap is small.
Clash of Clans
Base layouts anticipate human attackers' habits
Disciples III: Reincarnation
Mostly scripted AI; occasional human matches add slim prediction
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
Disciples III: Reincarnation
Map contents and loot are hidden until explored
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Clash of Clans
Army comps, upgrade paths, and attack routing
Disciples III: Reincarnation
Unit upgrade paths and fight sequencing are the solvable core
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.