head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, and it is a single point.

Optimization · Practiced Mastery
A cult RTS where peasants transform into warriors and micro decides skirmishes.

Optimization · Pure Optimization
Alternate-history RTS where economy management and build orders win wars.
Battle Realms leans Optimization (Practiced Mastery); 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.
Battle Realms
Real-time micro of small squads matters.
Command & Conquer: Red Alert
Micro and base management under time pressure
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Battle Realms
Human opponents adapt builds and harassment.
Command & Conquer: Red Alert
PvP skirmish rewards predicting enemy pushes
Command & Conquer: Red Alert leans a little harder on variance, though the gap is small.
Battle Realms
Minor map randomness.
Command & Conquer: Red Alert
Fog of war conceals army composition
Command & Conquer: Red Alert leans a little harder on optimization, though the gap is small.
Battle Realms
Peasant economy and unit upgrades solvable.
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.