head to head
Neither is simply harder - they are hard in different places. Portal 2 demands more execution; Workers & Resources: Soviet Republic demands more variance.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.

Optimization · Pure Optimization
Eastern-bloc planned-economy sim built on logistics chains.
Portal 2 leans Optimization (Pure Optimization); Workers & Resources: Soviet Republic leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
Portal 2
Portal placement requires some precision but timing is lenient.
Workers & Resources: Soviet Republic
no reflex
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal 2
No opponent; puzzles are static.
Workers & Resources: Soviet Republic
no adversary
Workers & Resources: Soviet Republic leans clearly harder on variance.
Portal 2
Puzzles are deterministic with no randomness.
Workers & Resources: Soviet Republic
weather, resource finds
Workers & Resources: Soviet Republic leans a little harder on optimization, though the gap is small.
Portal 2
Solving the puzzle's logic IS the entire game.
Workers & Resources: Soviet Republic
logistics chains and infrastructure central
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.