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

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

Optimization · Pure Optimization
A faction-routing RPG where custom spell combinations and allegiance optimization define the most efficient path.
Fallout: New Vegas leans Optimization (Pure Optimization); Tyranny leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Tyranny
Combat is secondary; faction routing and dialogue are the main skill axes
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout: New Vegas
Scripted factions and enemies
Tyranny
Scripted NPC factions respond to choices but follow fixed logic trees
Tyranny leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Tyranny
Skill check thresholds and hidden lore flags create unknown-information branches
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
Tyranny
Combo spell crafting and faction reputation routing reward system knowledge
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.