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

Execution · Twitch Chaos
GameCube kart racer with two riders per kart trading items mid-drift.

Execution · Pure Mechanics
Demolition derby racer with destructible PvP chaos.
Mario Kart: Double Dash!! leans Execution (Twitch Chaos); Wreckfest leans Execution (Pure Mechanics).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Kart: Double Dash!!
Two-character swaps and drift timing
Wreckfest
Demolition driving, ramming angles
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Kart: Double Dash!!
Item duels against humans reward baiting
Wreckfest
Online derby PvP rewards ramming reads
Mario Kart: Double Dash!! leans a little harder on variance, though the gap is small.
Mario Kart: Double Dash!!
Special item rolls swing races
Wreckfest
Crash physics chaos
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Kart: Double Dash!!
Character pairings and lines are solved
Wreckfest
Car upgrades and durability tuning
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.