head to head
Neither is simply harder - they are hard in different places. Age of Empires III demands more execution; Frozen Synapse demands more reads.

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

Reads · Mind & Math
A simultaneous-turn tactics game where you plot moves against a human's unseen plan and watch both resolve.
Age of Empires III leans Optimization (Mind & Math); Frozen Synapse leans Reads (Mind & Math).
Age of Empires III leans clearly harder on execution.
Age of Empires III
Unit micro and raid defense
Frozen Synapse
Simultaneous turns remove all dexterity
Frozen Synapse leans clearly harder on reads.
Age of Empires III
Human deck and timing reads in ranked
Frozen Synapse
You must predict a human's hidden plan each turn
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Age of Empires III
Map spawns and shipment ordering unknowns
Frozen Synapse
Hidden enemy orders and fog on some modes
Age of Empires III leans a little harder on optimization, though the gap is small.
Age of Empires III
Home-city decks are a build-crafting layer
Frozen Synapse
Line-of-sight geometry and timing are calculable
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.