head to head
Neither is simply harder - they are hard in different places. Dawn of Man demands more variance; Portal demands more execution.

Optimization · Pure Optimization
A prehistoric settlement survival builder about guiding a tribe from stone age to iron age.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Dawn of Man leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Dawn of Man
Light real-time camera and command work only.
Portal
Portal placement timing modest.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Dawn of Man
Raiders and animals follow scripted, predictable behaviour.
Portal
No adversary modeling player.
Dawn of Man leans clearly harder on variance.
Dawn of Man
Raid timing, weather and animal migrations add unknowns.
Portal
Deterministic chambers; no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Dawn of Man
Tech progression, food logistics and settlement layout decide survival.
Portal
Pure puzzle-solving optimization.
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.