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

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

Optimization · Pure Optimization
A timer-and-spreadsheet 4X where officer math and resource pipelines decide everything.
Clash of Clans leans Optimization (Pure Optimization); Star Trek Fleet Command 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.
Clash of Clans
Troop drop placement is forgiving
Star Trek Fleet Command
Menu taps and timers - no hands required
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
Star Trek Fleet Command
Rival alliances raid and retaliate, mildly worth predicting
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
Star Trek Fleet Command
Loot rolls and unscouted systems add hidden information
Clash of Clans leans a little harder on optimization, though the gap is small.
Clash of Clans
Army comps, upgrade paths, and attack routing
Star Trek Fleet Command
Officer synergies, ship tiers and resource pipelines are the real game
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.