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
Alternate-history RTS where economy management and build orders win wars.

Optimization · Pure Optimization
Fantasy RTS spin-off of Rise of Nations with three wildly asymmetric civilizations and hero units.
Command & Conquer: Red Alert leans Optimization (Pure Optimization); Rise of Nations: Rise of Legends 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.
Command & Conquer: Red Alert
Micro and base management under time pressure
Rise of Nations: Rise of Legends
Real-time economy and army juggling needs speed
Command & Conquer: Red Alert leans a little harder on reads, though the gap is small.
Command & Conquer: Red Alert
PvP skirmish rewards predicting enemy pushes
Rise of Nations: Rise of Legends
PvP rewards countering opponents' hero and tech commitments
Command & Conquer: Red Alert leans a little harder on variance, though the gap is small.
Command & Conquer: Red Alert
Fog of war conceals army composition
Rise of Nations: Rise of Legends
Map layouts and neutral sites vary
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Command & Conquer: Red Alert
Ore economy and build orders decide games
Rise of Nations: Rise of Legends
Asymmetric faction trees and expansion timing reward deep study
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.