head to head
Neither is simply harder - they are hard in different places. Portal demands more execution; Pro Evolution Soccer Management demands more variance.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.

Optimization · Pure Optimization
A football management sim about running a club.
Portal leans Optimization (Pure Optimization); Pro Evolution Soccer Management leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
Pro Evolution Soccer Management
no direct on-pitch input
Pro Evolution Soccer Management leans a little harder on reads, though the gap is small.
Portal
No adversary modeling player.
Pro Evolution Soccer Management
AI opposing managers barely adapt
Pro Evolution Soccer Management leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Pro Evolution Soccer Management
match simulation randomness
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
Pure puzzle-solving optimization.
Pro Evolution Soccer Management
squad building and tactics fully 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.