head to head
Call of Duty: Black Ops asks more than Digimon Rumble Arena 2, and the gap is execution.

Execution · Competitive PvP
Cold War-era shooter pairing twitch multiplayer with the cult Zombies mode.

Execution · Competitive PvP
A party platform fighter testing scramble execution and couch-rival prediction.
Call of Duty: Black Ops leans Execution (Competitive PvP); Digimon Rumble Arena 2 leans Execution (Competitive PvP).
Call of Duty: Black Ops leans clearly harder on execution.
Call of Duty: Black Ops
Gunfights hinge on aim and reaction speed
Digimon Rumble Arena 2
Smash-style movement and attack timing in chaotic arenas
Call of Duty: Black Ops leans a little harder on reads, though the gap is small.
Call of Duty: Black Ops
Reading human opponents' positioning and timing
Digimon Rumble Arena 2
Couch opponents bait digivolutions and punishes
Call of Duty: Black Ops leans a little harder on variance, though the gap is small.
Call of Duty: Black Ops
Spawns, care packages, zombies RNG
Digimon Rumble Arena 2
Item and power-up spawns shuffle fights
Call of Duty: Black Ops leans clearly harder on optimization.
Call of Duty: Black Ops
Class builds, map control, zombies routing
Digimon Rumble Arena 2
Character matchups and stage knowledge add light depth
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.