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

Execution · Pure Mechanics
Pure car control over loose surfaces, sharpened by memorising every stage.

Execution · Practiced Mastery
Precise rally car control over stages that reward memorisation and tuning.
Colin McRae Rally 2.0 leans Execution (Pure Mechanics); Dirt 3 leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Colin McRae Rally 2.0
Surface-specific car control at speed decides every stage
Dirt 3
Car control on loose surfaces is a high physical ceiling
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Colin McRae Rally 2.0
Time-trial format - no adaptive opponent on the stage
Dirt 3
Racing the clock or scripted AI, nobody adapts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Colin McRae Rally 2.0
Mid-stage surprises minimal once pace notes are internalised
Dirt 3
Surface conditions and minor physics noise per run
Dirt 3 leans a little harder on optimization, though the gap is small.
Colin McRae Rally 2.0
Memorising stages and tuning setups converges times steadily
Dirt 3
Stage knowledge and setup tuning reward 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.