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

Execution · Twitch Chaos
Kart racing execution moderated by item randomness and learnable track routes.

Execution · Twitch Chaos
A mobile racing runner testing reflex lane-play under item RNG and upgrade grind.
Sonic & All-Stars Racing Transformed leans Execution (Twitch Chaos); Sonic Forces: Speed Battle 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.
Sonic & All-Stars Racing Transformed
Drift timing and transforming vehicle control reward practice
Sonic Forces: Speed Battle
Lane-switch timing and trap dodging decide races
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic & All-Stars Racing Transformed
Human racers add light positional mind games
Sonic Forces: Speed Battle
Live opponents exist but interaction is mostly indirect items
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic & All-Stars Racing Transformed
Item rolls regularly upend race positions
Sonic Forces: Speed Battle
Item rolls and character gacha swing outcomes
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Sonic & All-Stars Racing Transformed
Track shortcuts and drift-boost routes are learnable
Sonic Forces: Speed Battle
Character upgrades and route knowledge compound over time
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.