head to head
Neither is simply harder - they are hard in different places. Jagged Alliance: Rage! demands more variance; Portal demands more execution.

Optimization · Pure Optimization
A turn-based mercenary tactics game about positioning and resource management.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Jagged Alliance: Rage! leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Jagged Alliance: Rage!
Turn-based, so no aim or reflex demand
Portal
Portal placement timing modest.
Jagged Alliance: Rage! leans clearly harder on reads.
Jagged Alliance: Rage!
Enemy AI is scripted, not adaptive to you
Portal
No adversary modeling player.
Jagged Alliance: Rage! leans clearly harder on variance.
Jagged Alliance: Rage!
Hit chances and ambush placement add randomness
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.
Jagged Alliance: Rage!
Positioning, action-point use and gear management decide fights
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.