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.

Optimization · Pure Optimization
Alternate-history RTS where economy management and build orders win wars.
Age of Empires III leans Optimization (Mind & Math); Command & Conquer: Red Alert 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.
Age of Empires III
Unit micro and raid defense
Command & Conquer: Red Alert
Micro and base management under time pressure
Age of Empires III leans a little harder on reads, though the gap is small.
Age of Empires III
Human deck and timing reads in ranked
Command & Conquer: Red Alert
PvP skirmish rewards predicting enemy pushes
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
Command & Conquer: Red Alert
Fog of war conceals army composition
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
Command & Conquer: Red Alert
Ore economy and build orders decide games
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.