head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Trilogy closer adding desert vehicles and dark-light eco powers to the formula.

Execution · Practiced Mastery
A 3D Sonic where you swap between three-character team formations mid-level.
Jak 3 leans Execution (Practiced Mastery); Sonic Heroes leans Execution (Practiced Mastery).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Jak 3
Platforming, shooting, and vehicle handling
Sonic Heroes
Speed sections punish sloppy control
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Jak 3
Enemies run fixed scripts
Sonic Heroes
Scripted enemies only
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Jak 3
Deterministic desert and city
Sonic Heroes
Fixed level layouts
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Jak 3
Upgrade paths and mission approach choices
Sonic Heroes
Team-formation switching and rank routes
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.