head to head
Neither is simply harder - they are hard in different places. Diplomacy demands more reads; Pokémon Battle Revolution demands more variance.

Reads · Pure Mind Games
A classic strategy game of negotiation and betrayal among nations.

Reads · Mind & Math
Predicting a human trainer's switches atop team-building math and damage rolls.
Diplomacy leans Reads (Pure Mind Games); Pokémon Battle Revolution leans Reads (Mind & Math).
Pokémon Battle Revolution leans a little harder on execution, though the gap is small.
Diplomacy
no physical skill, purely negotiation and planning
Pokémon Battle Revolution
Turn-based menu selection requires no dexterity
Diplomacy leans clearly harder on reads.
Diplomacy
reading and out-negotiating human players is core
Pokémon Battle Revolution
Wi-Fi battles hinge on predicting switches and protects
Pokémon Battle Revolution leans clearly harder on variance.
Diplomacy
no hidden info or randomness, pure information
Pokémon Battle Revolution
Damage rolls, crits and status procs sway turns
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Diplomacy
strategic alliance and movement planning solvable
Pokémon Battle Revolution
Team building and type-matchup math underpin every battle
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.