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
Execution on the ball plus constant prediction of the other player's shape.

Execution · Practiced Mastery
Stick execution and opponent prediction inside licensed tournament football.
Pro Evolution Soccer 2009 leans Execution (Competitive PvP); UEFA Champions League 2006–2007 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.
Pro Evolution Soccer 2009
Close control and finishing windows demand stick precision
UEFA Champions League 2006–2007
Pass timing and shot placement decide most goals
Pro Evolution Soccer 2009 leans a little harder on reads, though the gap is small.
Pro Evolution Soccer 2009
Online and couch opponents adjust tactics against you
UEFA Champions League 2006–2007
Human opponents bait tackles and disguise attacks
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Pro Evolution Soccer 2009
Ricochets and keeper parries add small randomness
UEFA Champions League 2006–2007
Deflections and AI bounces add match noise
UEFA Champions League 2006–2007 leans a little harder on optimization, though the gap is small.
Pro Evolution Soccer 2009
Squad setup and tactical sliders reward preparation
UEFA Champions League 2006–2007
Squad selection and tactical setup are solvable preparation
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.