head to head
Mario Kart 8 asks more than Pac-Man World Rally, and the gap is variance.

Execution · Twitch Chaos
A kart racer where controlled chaos from random items tempers otherwise precise driving skill.

Execution · Twitch Chaos
Kart racing where drift skill fights against item-roll chaos on themed tracks.
Mario Kart 8 leans Execution (Twitch Chaos); Pac-Man World Rally leans Execution (Twitch Chaos).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Mario Kart 8
precise drifting and item timing matter
Pac-Man World Rally
Drift timing and shortcut jumps decide clean laps
Pac-Man World Rally leans a little harder on reads, though the gap is small.
Mario Kart 8
minimal, mostly reacting not predicting
Pac-Man World Rally
Human races add light item-timing prediction
Mario Kart 8 leans clearly harder on variance.
Mario Kart 8
item boxes are heavily randomized
Pac-Man World Rally
Item rolls scramble positions every race
Mario Kart 8 leans a little harder on optimization, though the gap is small.
Mario Kart 8
track lines and item strategy solvable
Pac-Man World Rally
Track shortcuts and kart picks are learnable edges
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.