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 · Grand Arena
A tag-team crossover fighter pitting Street Fighter's cast against Tekken's under Capcom rules.

Execution · Grand Arena
A refined KOF entry that lowers the execution bar slightly while preserving the team-order reads and punish game.
Street Fighter X Tekken leans Execution (Grand Arena); The King of Fighters XV leans Execution (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter X Tekken
Tag combos and juggle timing demand practiced hands
The King of Fighters XV
Shatter Strike and MAX Mode combos demand practiced precise inputs
The King of Fighters XV leans a little harder on reads, though the gap is small.
Street Fighter X Tekken
Human mixups and tag baits require adaptation
The King of Fighters XV
Team order choices and opponent habit exploitation remain central
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter X Tekken
Deterministic aside from negligible elements
The King of Fighters XV
No RNG; all information is visible in the match
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Street Fighter X Tekken
Gem loadouts and team synergy add a builder layer
The King of Fighters XV
Team construction and MAX Mode routing reward study
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.