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

Execution · Pure Mechanics
Sequel rhythm game with harder setlists and refined plastic-guitar technique.

Execution · Pure Mechanics
Family-friendly rhythm charts where hitting scrolling notes on time is everything.
Guitar Hero II leans Execution (Pure Mechanics); LEGO Rock Band leans Execution (Pure Mechanics).
Guitar Hero II leans a little harder on execution, though the gap is small.
Guitar Hero II
Harder charts, hammer-ons, and three-note chords
LEGO Rock Band
Perfect inputs literally full-combo every chart
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Guitar Hero II
Static note highways
LEGO Rock Band
No opponent - charts never adapt
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Guitar Hero II
Fully deterministic charts
LEGO Rock Band
Note charts are fixed and visible
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Guitar Hero II
Star power pathing for leaderboard play
LEGO Rock Band
Overdrive activation timing is the only strategy layer
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.