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 · Competitive PvP
Football stick execution and opponent reading, salted with bounce-of-the-ball luck.

Execution · Competitive PvP
A wrestling game about timing grapples and, versus humans, reading reversals.
FIFA Soccer 07 leans Execution (Competitive PvP); WCW/nWo Thunder leans Execution (Competitive PvP).
FIFA Soccer 07 leans a little harder on execution, though the gap is small.
FIFA Soccer 07
Stick skills and timing on passes and finishing
WCW/nWo Thunder
Grapple and strike timing decide exchanges
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Soccer 07
Versus humans, baiting tackles and disguising attacks matters
WCW/nWo Thunder
Human opponents must be anticipated and countered
FIFA Soccer 07 leans a little harder on variance, though the gap is small.
FIFA Soccer 07
Deflections and keeper randomness swing single matches
WCW/nWo Thunder
Reversal windows add some unpredictability
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
FIFA Soccer 07
Formations and exploit patterns are learnable meta
WCW/nWo Thunder
Move-set knowledge and stamina management matter
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.