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

Optimization · Practiced Mastery
Revenge-driven open-worlder dismantling a sixties crime empire district by district.

Optimization · Practiced Mastery
A family-friendly open-world driving adventure romping through Springfield's mystery of cameras and cola.
Mafia III leans Optimization (Practiced Mastery); The Simpsons: Hit & Run 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.
Mafia III
Stealth takedowns and gunfights
The Simpsons: Hit & Run
Forgiving driving and light platforming
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mafia III
Racket guards follow fixed AI
The Simpsons: Hit & Run
No adaptive opposition exists
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Mafia III
Open world is static
The Simpsons: Hit & Run
Fixed missions with trivial traffic noise
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mafia III
District takeover loop and underboss assignments
The Simpsons: Hit & Run
Mission routes, shortcuts, and collectible runs are solvable
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.