head to head
Halo 4 asks more than Red Dead Redemption 2, and the gap is reads.

Execution · Practiced Mastery
343's debut pits Master Chief against the Didact with loadout-driven multiplayer.

Execution · Practiced Mastery
A cinematic open-world western leaning on shooting feel and atmosphere.
Halo 4 leans Execution (Practiced Mastery); Red Dead Redemption 2 leans Execution (Practiced Mastery).
Halo 4 leans clearly harder on execution.
Halo 4
Precision aim amid faster kill times
Red Dead Redemption 2
Gunplay and Dead Eye reward aim and timing.
Halo 4 leans clearly harder on reads.
Halo 4
Human opponents in Infinity multiplayer
Red Dead Redemption 2
Enemies use scripted AI patterns, not adaptation.
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Halo 4
Ordnance drops randomise mid-match rewards
Red Dead Redemption 2
Some hunting and weather randomness, lightly hidden.
Halo 4 leans a little harder on optimization, though the gap is small.
Halo 4
Loadout building and map control
Red Dead Redemption 2
Loadouts and routes solvable but loose.
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.