head to head
Left 4 Dead asks more than Sniper Elite 4, and the gap is variance.

Execution · Twitch Chaos
Co-op zombie shooter whose AI Director reshuffles every run to keep teams honest.

Execution · Practiced Mastery
Balancing ballistics execution with patrol timing to eliminate targets without triggering coordinated alerts.
Left 4 Dead leans Execution (Twitch Chaos); Sniper Elite 4 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.
Left 4 Dead
Headshots, melee shoves, and special-infected reaction time
Sniper Elite 4
Long-range ballistics, bullet drop, and wind compensation are the core demand
Left 4 Dead leans a little harder on reads, though the gap is small.
Left 4 Dead
Versus mode adds human ambush mindgames
Sniper Elite 4
Axis soldiers follow scripted patrol cycles without modelling the player
Left 4 Dead leans clearly harder on variance.
Left 4 Dead
AI Director randomizes hordes, items, and specials
Sniper Elite 4
Wind direction and enemy patrol timing add first-run uncertainty
Sniper Elite 4 leans a little harder on optimization, though the gap is small.
Left 4 Dead
Team spacing, route choice, and resource discipline
Sniper Elite 4
Synchronised shot timing and route planning reward methodical preparation
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.