head to head
Cossacks 3 asks more than Halo Wars, and the gap is optimization.

Optimization · Pure Optimization
A large-scale real-time strategy game about massive army economies in the 17th century.

Optimization · Mind & Math
Console-first RTS translating Halo's factions into streamlined base-and-army battles.
Cossacks 3 leans Optimization (Pure Optimization); Halo Wars 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.
Cossacks 3
unit micromanagement under real-time pressure
Halo Wars
Controller macro is deliberately light
Cossacks 3 leans a little harder on reads, though the gap is small.
Cossacks 3
human opponents bluff builds and attacks
Halo Wars
Versus humans, build choices are mindgames
Halo Wars leans a little harder on variance, though the gap is small.
Cossacks 3
minor combat outcome randomness
Halo Wars
Scouting hides enemy composition early
Cossacks 3 leans clearly harder on optimization.
Cossacks 3
massive army economy and tech optimization
Halo Wars
Build orders and counter-unit economy
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.