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 base-layout and attack-planning puzzle against static player defenses.

Optimization · Pure Optimization
Base-building strategy game about optimizing upgrade economy and raid compositions.
Boom Beach leans Optimization (Pure Optimization); Clash of Clans 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.
Boom Beach
Tapping troop deployments takes no dexterity
Clash of Clans
Troop drop placement is forgiving
Clash of Clans leans a little harder on reads, though the gap is small.
Boom Beach
Attacks hit static bases - defenders aren't present to adapt
Clash of Clans
Base layouts anticipate human attackers' habits
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Boom Beach
Scouting reveals most info; matchmaking adds some spread
Clash of Clans
Matchmaking and unseen traps add uncertainty
Clash of Clans leans a little harder on optimization, though the gap is small.
Boom Beach
Base layouts, troop compositions and timing are the solvable core
Clash of Clans
Army comps, upgrade paths, and attack routing
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.