head to head
Neither is simply harder - they are hard in different places. Fallout: New Vegas demands more execution; Kingdom: Classic demands more variance.

Optimization · Pure Optimization
A faction-driven RPG-shooter where build and route planning shape every ending.

Optimization · Pure Optimization
Managing a coin economy against escalating scripted raids with deliberately unexplained rules.
Fallout: New Vegas leans Optimization (Pure Optimization); Kingdom: Classic leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Kingdom: Classic
Riding left and right and dropping coins demands no twitch skill
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Kingdom: Classic
Greed waves follow scripted escalation, never adapt to you
Kingdom: Classic leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Kingdom: Classic
Unexplained mechanics and map layout are hidden until mapped
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Kingdom: Classic
Coin economy and wall timing 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.