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
Precision sniping and arena navigation through fixed, gimmick-laden levels.

Execution · Practiced Mastery
A Serious Sam-style horde shooter testing strafing aim against scripted waves.
MDK leans Execution (Practiced Mastery); Will Rock 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.
MDK
Sniper-mode precision and arena dodging demand steady hands
Will Rock
Circle-strafing huge enemy swarms is the whole test
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
MDK
Alien enemies behave on fixed scripts
Will Rock
Monsters charge in fixed spawned waves
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
MDK
Levels are authored with nothing random
Will Rock
Spawns are scripted and repeat identically
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
MDK
Learning arena gimmicks and item use solves each level
Will Rock
Weapon choice and arena positioning 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.