head to head
Neither is simply harder - they are hard in different places. Age of Empires III demands more execution; Gwent: The Witcher Card Game demands more reads.

Optimization · Mind & Math
A colonial-era RTS adding home-city card shipments to classic Age economy play.

Reads · Mind & Math
A bluffing-heavy card game where reading your opponent across three rounds outweighs raw card power.
Age of Empires III leans Optimization (Mind & Math); Gwent: The Witcher Card Game leans Reads (Mind & Math).
Age of Empires III leans clearly harder on execution.
Age of Empires III
Unit micro and raid defense
Gwent: The Witcher Card Game
No timing involved; purely strategic card placement
Gwent: The Witcher Card Game leans clearly harder on reads.
Age of Empires III
Human deck and timing reads in ranked
Gwent: The Witcher Card Game
Two-out-of-three rounds create meta-game bluffing and baiting
Gwent: The Witcher Card Game leans a little harder on variance, though the gap is small.
Age of Empires III
Map spawns and shipment ordering unknowns
Gwent: The Witcher Card Game
Card draws and hidden hand matter but deck is known
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Age of Empires III
Home-city decks are a build-crafting layer
Gwent: The Witcher Card Game
Row control and point denial strategies are analytically 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.