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

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

Optimization · Pure Optimization
The co-op evolution of the coin-dropping kingdom builder, now with persistent campaigns across themed settings.
Fallout: New Vegas leans Optimization (Pure Optimization); Kingdom Two Crowns leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Kingdom Two Crowns
Riding and coin placement only
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Kingdom Two Crowns
Greed attacks are systemic, not adaptive
Kingdom Two Crowns leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Kingdom Two Crowns
Procedural islands and mount locations vary
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 Two Crowns
Build order and portal-clearing strategy dominate
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.