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
Card-battle strategy testing deckbuilding math against draw luck.

Optimization · Pure Optimization
A grand strategy 4X where empire optimization carries you through random crises.
Etherlords II leans Optimization (Pure Optimization); Stellaris 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.
Etherlords II
Turn-based card play, no dexterity
Stellaris
Real-time pausable with no input precision.
Stellaris leans a little harder on reads, though the gap is small.
Etherlords II
Mostly AI duels; rare human matches add light bluffing
Stellaris
AI is scripted; multiplayer adds modest adaptation.
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
Stellaris
Galaxy gen, anomalies, and crises vary widely.
Stellaris leans a little harder on optimization, though the gap is small.
Etherlords II
Deck construction and mana sequencing are deeply solvable
Stellaris
Empire builds, fleet comps, and economy dominate.
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.