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

Optimization · Pure Optimization
Managing a coin economy against escalating scripted raids with deliberately unexplained rules.

Optimization · Systems & Chaos
Managing a survivor community's economy and risk under permadeath randomness.
Kingdom: Classic leans Optimization (Pure Optimization); State of Decay 2 leans Optimization (Systems & Chaos).
State of Decay 2 leans a little harder on execution, though the gap is small.
Kingdom: Classic
Riding left and right and dropping coins demands no twitch skill
State of Decay 2
Combat is forgiving; stealth and swings need modest timing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Kingdom: Classic
Greed waves follow scripted escalation, never adapt to you
State of Decay 2
Zombies and hostile NPCs follow randomised scripts
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Kingdom: Classic
Unexplained mechanics and map layout are hidden until mapped
State of Decay 2
Permadeath, infestations and survivor traits randomise each community
Kingdom: Classic leans a little harder on optimization, though the gap is small.
Kingdom: Classic
Coin economy and wall timing are the solvable core
State of Decay 2
Base building, resource routing and survivor management drive survival
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.