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
The original loot-driven co-op shooter set on the bandit world of Pandora.

Execution · Practiced Mastery
Claustrophobic post-apocalyptic shooter where bullets double as currency.
Borderlands leans Optimization (Practiced Mastery); Metro 2033 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.
Borderlands
Standard FPS aim; numbers matter more than precision
Metro 2033
scarce-ammo gunfights punish sloppy aim
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Borderlands
Bandits and skags are scripted
Metro 2033
mutants and bandits follow scripts
Borderlands leans a little harder on variance, though the gap is small.
Borderlands
Procedural loot drops gate your power
Metro 2033
hidden moral points and supplies first run
Borderlands leans a little harder on optimization, though the gap is small.
Borderlands
Builds, gear math, and farming routes dominate
Metro 2033
ammo-as-currency economy and stealth routing
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.