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 3D fighter layering team optimization onto Tekken's execution and reads core.

Reads · Grand Arena
A neutral-focused fighter where managing the GRD gauge against an adapting opponent creates a constant strategic tug-of-war.
Tekken Tag Tournament leans Execution (Grand Arena); Under Night In-Birth II Sys:Celes leans Reads (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Tekken Tag Tournament
Tag combos and netsu juggles demand precise inputs
Under Night In-Birth II Sys:Celes
GRD-boosted combos and precise Chain Shift timing demand real execution
Under Night In-Birth II Sys:Celes leans a little harder on reads, though the gap is small.
Tekken Tag Tournament
Tag timing adds another layer of human mind-games
Under Night In-Birth II Sys:Celes
GRD tug-of-war with a human opponent is persistently adaptive
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Tekken Tag Tournament
Open information; nothing hidden between rounds
Under Night In-Birth II Sys:Celes
No RNG; GRD state is visible information
Under Night In-Birth II Sys:Celes leans a little harder on optimization, though the gap is small.
Tekken Tag Tournament
Team synergy and tag combo routing are optimizable systems
Under Night In-Birth II Sys:Celes
GRD management theory and optimal punish routing are well-documented
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.