head to head
Neither is simply harder - they are hard in different places. Fallout: New Vegas demands more execution; Rise of Kingdoms demands more reads.

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

Optimization · Pure Optimization
Long-horizon resource and commander optimization with alliance-war prediction at the top end.
Fallout: New Vegas leans Optimization (Pure Optimization); Rise of Kingdoms leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Rise of Kingdoms
Tapping commands has no physical ceiling
Rise of Kingdoms leans clearly harder on reads.
Fallout: New Vegas
Scripted factions and enemies
Rise of Kingdoms
Alliance wars involve outguessing rival players' timing and targets
Rise of Kingdoms leans a little harder on variance, though the gap is small.
Fallout: New Vegas
Some loot and crit RNG
Rise of Kingdoms
Commander pulls and event rolls gate progression
Fallout: New Vegas leans a little harder on optimization, though the gap is small.
Fallout: New Vegas
Faction routing, perks, builds heavily rewarded
Rise of Kingdoms
Build queues, commander pairings and resource math 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.