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 · Practiced Mastery
Backyard survival testing crafting optimisation with timing-based bug combat.

Optimization · Practiced Mastery
Bethesda space RPG with ship and outpost systems.
Grounded 2 leans Optimization (Practiced Mastery); Starfield leans Optimization (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Grounded 2
Dodging and perfect-blocking giant bugs takes real timing
Starfield
Shooter and piloting inputs
Starfield leans a little harder on reads, though the gap is small.
Grounded 2
Insect AI follows mappable behaviour patterns
Starfield
Scripted NPC AI patterns
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grounded 2
World discovery and resource spawns hide some information
Starfield
Procedural planets, loot variance
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Grounded 2
Base building, armor builds and tech routing drive progress
Starfield
Ship building, outpost, perk routing
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.