head to head
Neither is simply harder - they are hard in different places. Conker: Live & Reloaded demands more reads; Grand Theft Auto: San Andreas demands more optimization.

Execution · Practiced Mastery
A scripted comedy platformer paired with class-based team shooting and map control.

Optimization · Practiced Mastery
A sprawling open-world crime epic with RPG-style character stats across a whole state.
Conker: Live & Reloaded leans Execution (Practiced Mastery); Grand Theft Auto: San Andreas leans Optimization (Practiced Mastery).
Conker: Live & Reloaded leans clearly harder on execution.
Conker: Live & Reloaded
Class shooter multiplayer rewards aim; campaign platforming is moderate
Grand Theft Auto: San Andreas
Flying school and drive-bys need decent hands
Conker: Live & Reloaded leans clearly harder on reads.
Conker: Live & Reloaded
Team versus matches add modest opponent prediction
Grand Theft Auto: San Andreas
Gang AI is scripted, never adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Conker: Live & Reloaded
Mostly deterministic with light spawn noise
Grand Theft Auto: San Andreas
Territory wars and traffic add light randomness
Grand Theft Auto: San Andreas leans clearly harder on optimization.
Conker: Live & Reloaded
Class roles and map control reward study
Grand Theft Auto: San Andreas
Stats, gym, weapon skill, and routes reward systematic play
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.