head to head
Shogun: Total War asks more than Portal, and the gap is variance.

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

Optimization · Pure Optimization
A strategy wargame pairing turn-based management of feudal Japan with real-time mass battles.
Portal leans Optimization (Pure Optimization); Shogun: Total War leans Optimization (Pure Optimization).
Portal leans a little harder on execution, though the gap is small.
Portal
Portal placement timing modest.
Shogun: Total War
Real-time battle micro matters but pace is forgiving
Shogun: Total War leans clearly harder on reads.
Portal
No adversary modeling player.
Shogun: Total War
Campaign AI daimyos follow mappable behaviors
Shogun: Total War leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
Shogun: Total War
Fog of war and agent rolls hide information
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.
Shogun: Total War
Campaign economy, army composition and terrain are deeply 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.