head to head
Neither is harder. They score identically on all four axes, so the difference between them is in kind, not degree.

Execution · Practiced Mastery
Mars-mining rebellion FPS famous for letting you blast through the terrain itself.

Execution · Practiced Mastery
Patient ballistic aiming wrapped in plannable stealth positioning.
Red Faction leans Execution (Practiced Mastery); Sniper Elite V2 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.
Red Faction
Classic FPS aim and movement carry the campaign.
Sniper Elite V2
Ballistics-compensated long shots demand steady precise aim
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Red Faction
Scripted guards; multiplayer was a minor side mode.
Sniper Elite V2
Enemy AI runs fixed alert routines
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Red Faction
Unknown level layouts first time through.
Sniper Elite V2
Wind and patrol details vary slightly per attempt
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Red Faction
Geo-Mod tunneling and route knowledge open solvable shortcuts.
Sniper Elite V2
Positioning, sound masking and route planning are learnable
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.