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
Card-battle strategy testing deckbuilding math against draw luck.

Optimization · Systems & Chaos
Solvable micro-tactics puzzles gated by gacha luck over unit ownership.
Etherlords II leans Optimization (Pure Optimization); Fire Emblem Heroes leans Optimization (Systems & Chaos).
Fire Emblem Heroes leans a little harder on execution, though the gap is small.
Etherlords II
Turn-based card play, no dexterity
Fire Emblem Heroes
Drag-and-drop tactics need no dexterity
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Etherlords II
Mostly AI duels; rare human matches add light bluffing
Fire Emblem Heroes
Arena defense teams are AI-run, so prediction is shallow
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Etherlords II
Card draws decide what each duel offers
Fire Emblem Heroes
Gacha summoning rolls gate which units you even own
Etherlords II leans a little harder on optimization, though the gap is small.
Etherlords II
Deck construction and mana sequencing are deeply solvable
Fire Emblem Heroes
Skill inheritance, team building and tile math are deeply solvable
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.