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

Execution · Competitive PvP
Reflex disc rallies decided by throw precision and outguessing the human opponent.

Execution · Competitive PvP
Wrestling crude controls to land specials while outguessing a human opponent.
Disc Jam leans Execution (Competitive PvP); Street Fighter leans Execution (Competitive PvP).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Disc Jam
Volley timing, angles and positioning are pure reflex
Street Fighter
Notoriously stiff inputs make landing specials the real fight
Disc Jam leans a little harder on reads, though the gap is small.
Disc Jam
Rallies are won by faking out the human across the net
Street Fighter
Human versus rounds still reward bait and punish
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Disc Jam
Physics are consistent, almost nothing random
Street Fighter
Nothing hidden between two visible fighters
Disc Jam leans a little harder on optimization, though the gap is small.
Disc Jam
Character kits and throw tech form a thin meta
Street Fighter
Tiny moveset leaves little system to solve
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.