head to head
Borderlands 2 asks more than X-COM: UFO Defense, and the gap is execution.

Optimization · Systems & Chaos
Loot-shooter RPG built on gear chasing.

Optimization · Systems & Chaos
Seminal 1994 strategy game mixing global base management with brutal turn-based alien squad combat.
Borderlands 2 leans Optimization (Systems & Chaos); X-COM: UFO Defense leans Optimization (Systems & Chaos).
Borderlands 2 leans clearly harder on execution.
Borderlands 2
Aim matters but generous hit feel
X-COM: UFO Defense
Turn-based; only inventory clicking
Borderlands 2 leans a little harder on reads, though the gap is small.
Borderlands 2
Enemies are scripted loot fodder
X-COM: UFO Defense
Alien 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.
Borderlands 2
Procedurally generated weapon drops vary
X-COM: UFO Defense
Hit rolls, random maps, and unseen aliens punish constantly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Borderlands 2
Skill trees and gear math heavily solved
X-COM: UFO Defense
Base economy, research order, and tactical doctrine are masterable
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.