head to head
Sniper Elite III asks more than Grand Theft Auto V, and the gap is optimization.

Execution · Practiced Mastery
Sandbox crime playground spanning shooting, driving, and a persistent online economy.

Execution · Practiced Mastery
Plannable stealth routing punctuated by precise ballistic marksmanship.
Grand Theft Auto V leans Execution (Practiced Mastery); Sniper Elite III leans Execution (Practiced Mastery).
Sniper Elite III leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Sniper Elite III
Ballistic long shots demand steady, compensated aim
Grand Theft Auto V leans a little harder on reads, though the gap is small.
Grand Theft Auto V
Online PvP exists but mostly gear/positioning, not modeling.
Sniper Elite III
Enemy AI follows mappable alert and search routines
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Grand Theft Auto V
Some mission and lobby randomness.
Sniper Elite III
Patrol details and wind vary slightly per attempt
Sniper Elite III leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Sniper Elite III
Open maps reward planned routes, sound masking and relocation
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.