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

Optimization · Practiced Mastery
Trap-maze economics against human attackers who adapt their pushes.
Command & Conquer: Red Alert leans Optimization (Pure Optimization); Orcs Must Die! Unchained leans Optimization (Practiced Mastery).
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
Orcs Must Die! Unchained
Third-person combat matters but traps do the killing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Command & Conquer: Red Alert
PvP skirmish rewards predicting enemy pushes
Orcs Must Die! Unchained
PvP sieges reward predicting enemy pushes and trap placement
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
Orcs Must Die! Unchained
Card draws and minion waves add mild noise
Command & Conquer: Red Alert leans a little harder on optimization, though the gap is small.
Command & Conquer: Red Alert
Ore economy and build orders decide games
Orcs Must Die! Unchained
Trap economy and maze layout theory decide fortresses
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.