head to head
Neither is meaningfully harder - they pose close to the same test. The widest gap is execution, and it is a single point.

Optimization · Practiced Mastery
Series finale blending stealth with active battlefields and heavy cinematics.

Execution · Practiced Mastery
Ballistics compensation along tightly scripted sniping corridors.
Metal Gear Solid 4: Guns of the Patriots leans Optimization (Practiced Mastery); Sniper: Ghost Warrior 2 leans Execution (Practiced Mastery).
Sniper: Ghost Warrior 2 leans a little harder on execution, though the gap is small.
Metal Gear Solid 4: Guns of the Patriots
flexible gunplay alongside sneaking
Sniper: Ghost Warrior 2
Breath control, wind and drop compensation on every shot
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Solid 4: Guns of the Patriots
battlefield factions act on scripts
Sniper: Ghost Warrior 2
Enemies run scripted patrols and alarms
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Metal Gear Solid 4: Guns of the Patriots
mid-battle chaos mostly cosmetic
Sniper: Ghost Warrior 2
Wind values randomise individual shot solutions
Metal Gear Solid 4: Guns of the Patriots leans a little harder on optimization, though the gap is small.
Metal Gear Solid 4: Guns of the Patriots
camo, gear, and route knowledge per act
Sniper: Ghost Warrior 2
Memorising target sequences and stealth routes carries missions
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.