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
A near-future Call of Duty with squad-focused multiplayer and the Extinction mode.

Execution · Competitive PvP
A rugby simulation testing input timing and tactical play against opponents.
Call of Duty: Ghosts leans Execution (Practiced Mastery); Rugby World Cup 2015 leans Execution (Competitive PvP).
Call of Duty: Ghosts leans a little harder on execution, though the gap is small.
Call of Duty: Ghosts
Fast time-to-kill rewards first-shot aim
Rugby World Cup 2015
Timing passes, tackles, and kicks needs consistent inputs
Rugby World Cup 2015 leans a little harder on reads, though the gap is small.
Call of Duty: Ghosts
Outguessing human routes and peeks matters
Rugby World Cup 2015
Human opponents can be read in multiplayer matches
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Ghosts
Spawns and lobby matchups add noise
Rugby World Cup 2015
Ball bounces and AI add some unpredictability
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Call of Duty: Ghosts
Loadout and map knowledge are solvable layers
Rugby World Cup 2015
Set plays, team selection, and tactics form a systems layer
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.