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

Reads · Mind & Math
Objective-driven MOBA with shared team XP.
Age of Empires III leans Optimization (Mind & Math); Heroes of the Storm leans Reads (Mind & Math).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Age of Empires III
Unit micro and raid defense
Heroes of the Storm
Skillshots and rotations require hands
Heroes of the Storm leans a little harder on reads, though the gap is small.
Age of Empires III
Human deck and timing reads in ranked
Heroes of the Storm
Team-fight cooldown trading is prediction
Age of Empires III leans a little harder on variance, though the gap is small.
Age of Empires III
Map spawns and shipment ordering unknowns
Heroes of the Storm
Map objectives and merc camps vary
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
Heroes of the Storm
Talent picks and team comps deep
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.