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.

Optimization · Pure Optimization
A stealth puzzle game where meticulously planning the perfect assassination route is the whole point.

Optimization · Pure Optimization
Lane defense classic about managing a sun economy against shambling waves.
Hitman leans Optimization (Pure Optimization); Plants vs. Zombies leans Optimization (Pure Optimization).
Hitman leans a little harder on execution, though the gap is small.
Hitman
minimal twitch skill, stealth-focused
Plants vs. Zombies
Clicking to plant, minimal pressure
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Hitman
guard patrols scripted, no adaptation
Plants vs. Zombies
Zombie waves follow set compositions
Plants vs. Zombies leans a little harder on variance, though the gap is small.
Hitman
some random guard behavior variance
Plants vs. Zombies
Wave timing and lane pressure vary mildly
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Hitman
planning routes and disguises is fully solvable
Plants vs. Zombies
Sun economy and lane setups are near-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.