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 · Competitive PvP
Stick precision and constant prediction of a human opponent's tactical habits.

Execution · Competitive PvP
Class-based team shooter with deep mind games.
Pro Evolution Soccer 2015 leans Execution (Competitive PvP); Team Fortress 2 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.
Pro Evolution Soccer 2015
First touch, through-ball timing and finishing demand precise sticks
Team Fortress 2
Projectile aim and rocket jumps reward hands
Team Fortress 2 leans a little harder on reads, though the gap is small.
Pro Evolution Soccer 2015
Human opponents bait, switch tactics and punish habits
Team Fortress 2
Spy/sniper duels are pure prediction
Team Fortress 2 leans a little harder on variance, though the gap is small.
Pro Evolution Soccer 2015
Deflections and referee calls add bounded chaos
Team Fortress 2
Random crits and spread inject RNG
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Pro Evolution Soccer 2015
Formations, player roles and set pieces reward study
Team Fortress 2
Class loadouts and map routes 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.