head to head
Total War: Rome II asks more than Fallout: New Vegas, and the gap is reads.

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

Optimization · Pure Optimization
Maintaining senate favor and province chains while executing real-time cohort tactics.
Fallout: New Vegas leans Optimization (Pure Optimization); Total War: Rome II leans Optimization (Pure Optimization).
Total War: Rome II leans a little harder on execution, though the gap is small.
Fallout: New Vegas
Shooter inputs with VATS assist
Total War: Rome II
Cohort line management and flanking cavalry demand real-time micro
Total War: Rome II leans clearly harder on reads.
Fallout: New Vegas
Scripted factions and enemies
Total War: Rome II
AI generals follow scripted behaviors without adapting to the player
Total War: Rome II leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Total War: Rome II
Random political events and dynastic loyalty shifts add campaign variance
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
Total War: Rome II
Senate favor management and province chains form a solvable campaign system
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.