head to head
Neither is simply harder - they are hard in different places. Fallout: New Vegas demands more execution; Wizardry: Tale of the Forsaken Land demands more variance.

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

Optimization · Pure Optimization
A classic dungeon-crawling RPG demanding careful party and resource management.
Fallout: New Vegas leans Optimization (Pure Optimization); Wizardry: Tale of the Forsaken Land leans Optimization (Pure Optimization).
Fallout: New Vegas leans clearly harder on execution.
Fallout: New Vegas
Shooter inputs with VATS assist
Wizardry: Tale of the Forsaken Land
turn-based menu combat, no physical skill
Fallout: New Vegas leans a little harder on reads, though the gap is small.
Fallout: New Vegas
Scripted factions and enemies
Wizardry: Tale of the Forsaken Land
fixed dungeon monsters, no adaptive opponent
Wizardry: Tale of the Forsaken Land leans clearly harder on variance.
Fallout: New Vegas
Some loot and crit RNG
Wizardry: Tale of the Forsaken Land
random encounters, loot and hit-chance rolls
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
Wizardry: Tale of the Forsaken Land
party building, dungeon mapping, stat optimization
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.