head to head
Neither is simply harder - they are hard in different places. Pokémon Battle Revolution demands more optimization; Spy vs Spy demands more execution.

Reads · Mind & Math
Predicting a human trainer's switches atop team-building math and damage rolls.

Reads · Pure Mind Games
A split-screen trap duel testing prediction of where your human rival hid the bombs.
Pokémon Battle Revolution leans Reads (Mind & Math); Spy vs Spy leans Reads (Pure Mind Games).
Spy vs Spy leans clearly harder on execution.
Pokémon Battle Revolution
Turn-based menu selection requires no dexterity
Spy vs Spy
Simple movement and item fiddling under time pressure
Spy vs Spy leans a little harder on reads, though the gap is small.
Pokémon Battle Revolution
Wi-Fi battles hinge on predicting switches and protects
Spy vs Spy
Guessing where the rival spy laid traps is the core duel
Same score on variance - which means the number cannot separate them. The difference is in what each one asks of you.
Pokémon Battle Revolution
Damage rolls, crits and status procs sway turns
Spy vs Spy
Item locations are hidden information each round
Pokémon Battle Revolution leans clearly harder on optimization.
Pokémon Battle Revolution
Team building and type-matchup math underpin every battle
Spy vs Spy
Trap-and-counter knowledge forms a learnable layer
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.