head to head
Neither is simply harder - they are hard in different places. Might and Magic VII: For Blood and Honor demands more variance; Portal demands more execution.

Optimization · Pure Optimization
An open-world party blobber where promotion paths and skill routing matter far more than aim.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.
Might and Magic VII: For Blood and Honor leans Optimization (Pure Optimization); Portal leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Might and Magic VII: For Blood and Honor
Pausable party combat; minimal dexterity.
Portal
Portal placement timing modest.
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Might and Magic VII: For Blood and Honor
Enemies charge on fixed logic.
Portal
No adversary modeling player.
Might and Magic VII: For Blood and Honor leans clearly harder on variance.
Might and Magic VII: For Blood and Honor
Loot rolls and unknown dungeon contents first time.
Portal
Deterministic chambers; no randomness.
Same score on optimization - which means the number cannot separate them. The difference is in what each one asks of you.
Might and Magic VII: For Blood and Honor
Class promotions, skill points, and routing are fully solvable.
Portal
Pure puzzle-solving optimization.
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.