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
WWII grand strategy: templates, production, and focus paths.

Optimization · Pure Optimization
Optimizing Wielder builds and resource networks to project force in PvP or solo campaigns.
Hearts of Iron IV leans Optimization (Pure Optimization); Songs of Conquest 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.
Hearts of Iron IV
pausable, micromanagement-heavy
Songs of Conquest
Turn-based throughout; no timing demands
Hearts of Iron IV leans a little harder on reads, though the gap is small.
Hearts of Iron IV
PvP partly, mostly scripted AI
Songs of Conquest
Human PvP multiplayer creates opponent prediction pressure
Songs of Conquest leans a little harder on variance, though the gap is small.
Hearts of Iron IV
focus tree branches, events
Songs of Conquest
Resource tile placement and battle spell procs add variance
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Hearts of Iron IV
division templates and production solved
Songs of Conquest
Wielder skill trees, unit stacking, and map control routing are the optimization core
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.