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

Execution · Practiced Mastery
The sequel adding Horde mode to the campaign-plus-versus cover shooter formula.

Execution · Practiced Mastery
Artillery aim under wind combined with fort economy planning against human opponents.
Gears of War 2 leans Execution (Practiced Mastery); Worms Forts: Under Siege leans Execution (Practiced Mastery).
Gears of War 2 leans a little harder on execution, though the gap is small.
Gears of War 2
Gnasher battles and movement tech set the ceiling
Worms Forts: Under Siege
Manual trajectory aiming under wind decides each shot
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 2
Human opponents in versus drive prediction play
Worms Forts: Under Siege
Human opponents to outguess on building and target priorities
Worms Forts: Under Siege leans a little harder on variance, though the gap is small.
Gears of War 2
Horde spawns add mild randomness
Worms Forts: Under Siege
Wind, crates and terrain damage randomize turns
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 2
Power-weapon timing and positioning are solvable
Worms Forts: Under Siege
Fort placement and weapon-tech economy reward planning
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.