head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is reads, and it is a single point.

Optimization · Pure Optimization
A VATS-heavy wasteland RPG won by perk and build optimization.

Optimization · Pure Optimization
A charming turn-based RPG where timed button presses add light dexterity to simple optimization.
Fallout 3 leans Optimization (Pure Optimization); Super Mario RPG: Legend of the Seven Stars leans Optimization (Pure Optimization).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout 3
VATS-leaning combat, low aim demand
Super Mario RPG: Legend of the Seven Stars
Timed hits and blocks reward rhythm.
Fallout 3 leans a little harder on reads, though the gap is small.
Fallout 3
Scripted enemies
Super Mario RPG: Legend of the Seven Stars
Bosses use fixed attack scripts.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout 3
Loot rolls, SPECIAL checks
Super Mario RPG: Legend of the Seven Stars
Hidden chests and first-run boss surprises.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Fallout 3
Perk and build planning carries the run
Super Mario RPG: Legend of the Seven Stars
Gear, timing knowledge, and stat routing solve fights.
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.