head to head
Halo 3: ODST 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
Moody Halo side story about ordinary troopers piecing together a night in New Mombasa.
Grand Theft Auto V leans Execution (Practiced Mastery); Halo 3: ODST leans Execution (Practiced Mastery).
Halo 3: ODST leans a little harder on execution, though the gap is small.
Grand Theft Auto V
Driving and shooting demand decent inputs.
Halo 3: ODST
Squishier soldier demands careful aim and positioning
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.
Halo 3: ODST
Covenant patrols are scripted, not adaptive
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.
Halo 3: ODST
Open Mombasa hides clues until found
Halo 3: ODST leans clearly harder on optimization.
Grand Theft Auto V
Heists, money loops, builds learnable.
Halo 3: ODST
Firefight wave knowledge and route planning
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.