head to head
Hearts of Iron IV asks more than Tom Clancy's EndWar, and the gap is optimization.

Optimization · Pure Optimization
WWII grand strategy: templates, production, and focus paths.

Optimization · Mind & Math
Counter-picking units and out-planning opponents with your voice instead of clicks.
Hearts of Iron IV leans Optimization (Pure Optimization); Tom Clancy's EndWar leans Optimization (Mind & Math).
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
Tom Clancy's EndWar
Voice commands remove most mechanical demand by design
Tom Clancy's EndWar leans a little harder on reads, though the gap is small.
Hearts of Iron IV
PvP partly, mostly scripted AI
Tom Clancy's EndWar
Multiplayer theatre battles reward predicting enemy unit commitments
Hearts of Iron IV leans a little harder on variance, though the gap is small.
Hearts of Iron IV
focus tree branches, events
Tom Clancy's EndWar
Fog of war hides compositions until scouted
Hearts of Iron IV leans clearly harder on optimization.
Hearts of Iron IV
division templates and production solved
Tom Clancy's EndWar
Rock-paper-scissors unit counters and upgrade economy are the solvable 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.