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
Arena duels mixing twitch dodge-punish play with RPG build preparation.

Execution · Practiced Mastery
The sequel adding Horde mode to the campaign-plus-versus cover shooter formula.
Dissidia Final Fantasy leans Execution (Practiced Mastery); Gears of War 2 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.
Dissidia Final Fantasy
Aerial dashes, dodge timing and punishes demand fast hands
Gears of War 2
Gnasher battles and movement tech set the ceiling
Dissidia Final Fantasy leans a little harder on reads, though the gap is small.
Dissidia Final Fantasy
Human duels hinge on baiting bravery attacks and dodges
Gears of War 2
Human opponents in versus drive prediction play
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Dissidia Final Fantasy
Some equipment and summon randomness, mostly known state
Gears of War 2
Horde spawns add mild randomness
Dissidia Final Fantasy leans a little harder on optimization, though the gap is small.
Dissidia Final Fantasy
Builds, accessories and matchup knowledge shape every duel
Gears of War 2
Power-weapon timing and positioning are 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.