head to head
Neither is simply harder - they are hard in different places. Breach & Clear demands more variance; Portal 2 demands more execution.

Optimization · Pure Optimization
Planning optimal squad loadouts and synchronized room entries against scripted enemies.

Optimization · Pure Optimization
A first-person puzzle game where seeing the solution is the whole skill.
Breach & Clear leans Optimization (Pure Optimization); Portal 2 leans Optimization (Pure Optimization).
Portal 2 leans clearly harder on execution.
Breach & Clear
Turn-based orders remove any twitch demand
Portal 2
Portal placement requires some precision but timing is lenient.
Breach & Clear leans a little harder on reads, though the gap is small.
Breach & Clear
Enemy AI follows scripted placements, not adaptation
Portal 2
No opponent; puzzles are static.
Breach & Clear leans clearly harder on variance.
Breach & Clear
Enemy positions unknown until breached, then mappable
Portal 2
Puzzles are deterministic with no randomness.
Portal 2 leans a little harder on optimization, though the gap is small.
Breach & Clear
Squad builds and synchronized entry plans are the game
Portal 2
Solving the puzzle's logic IS the entire game.
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.