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

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

Execution · Competitive PvP
A hero battle royale where teamwork and aim against human opponents decides fights.
Gears of War 2 leans Execution (Practiced Mastery); My Hero Ultra Rumble leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Gears of War 2
Gnasher battles and movement tech set the ceiling
My Hero Ultra Rumble
aim and combo timing in battles
My Hero Ultra Rumble leans a little harder on reads, though the gap is small.
Gears of War 2
Human opponents in versus drive prediction play
My Hero Ultra Rumble
predicting human opponent tactics
My Hero Ultra Rumble leans a little harder on variance, though the gap is small.
Gears of War 2
Horde spawns add mild randomness
My Hero Ultra Rumble
item and loot drops are random
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
My Hero Ultra Rumble
team comps and loadouts solvable
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.