head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is variance, 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
Shot timing and play-calling against opponents who scheme around your habits.
FIFA Soccer 07 leans Execution (Competitive PvP); NBA 2K16 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.
FIFA Soccer 07
Stick skills and timing on passes and finishing
NBA 2K16
Shot-stick timing and dribble moves gate every possession
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
NBA 2K16
Online opponents adjust defensive schemes against your tendencies
FIFA Soccer 07 leans a little harder on variance, though the gap is small.
FIFA Soccer 07
Deflections and keeper randomness swing single matches
NBA 2K16
Shot RNG and card packs add bounded randomness
NBA 2K16 leans a little harder on optimization, though the gap is small.
FIFA Soccer 07
Formations and exploit patterns are learnable meta
NBA 2K16
Playbooks, rotations and roster building reward deep study
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.