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
Isometric co-op puzzling testing coordination and trap-room solutions.

Optimization · Practiced Mastery
Revenge-driven open-worlder dismantling a sixties crime empire district by district.
Lara Croft and the Temple of Osiris leans Optimization (Practiced Mastery); Mafia III 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.
Lara Croft and the Temple of Osiris
Twin-stick aiming and trap dodging take light skill
Mafia III
Stealth takedowns and gunfights
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Lara Croft and the Temple of Osiris
Enemies swarm on fixed triggers
Mafia III
Racket guards follow fixed AI
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Lara Croft and the Temple of Osiris
Puzzle and trap layouts are fixed once seen
Mafia III
Open world is static
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Lara Croft and the Temple of Osiris
Co-op puzzle solving and score routing lead the test
Mafia III
District takeover loop and underboss assignments
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.