head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Optimization · Pure Optimization
A 3rd Edition ruleset combat puzzle where multi-classing and feat selection unlock dominant strategies.

Optimization · Pure Optimization
Mastering interlocking social engineering and tech-tree systems on a programmable alien world.
Icewind Dale II leans Optimization (Pure Optimization); Sid Meier's Alpha Centauri leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Icewind Dale II
Real-time-with-pause negates twitch requirements
Sid Meier's Alpha Centauri
Turn-based; no twitch element at all
Sid Meier's Alpha Centauri leans a little harder on reads, though the gap is small.
Icewind Dale II
Scripted enemy routines offer nothing to read or predict adaptively
Sid Meier's Alpha Centauri
AI faction leaders follow fixed personality scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Icewind Dale II
3E feat combinations and hidden enemy resistances create unknown-information layers
Sid Meier's Alpha Centauri
Xenofungus and psi combat add some irreducible randomness
Sid Meier's Alpha Centauri leans a little harder on optimization, though the gap is small.
Icewind Dale II
3rd Edition feat optimization and multi-class architecture dominate success
Sid Meier's Alpha Centauri
Tech tree, social engineering, and base placement are essentially 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.