head to head
Neither is simply harder - they are hard in different places. Portal demands more execution; The Excavation of Hob's Barrow demands more variance.

Optimization · Pure Optimization
The portal-gun puzzle game whose solutions are everything.

Optimization · Pure Optimization
A folk horror adventure about an antiquarian unearthing something best left buried on the moors.
Portal leans Optimization (Pure Optimization); The Excavation of Hob's Barrow leans Optimization (Pure Optimization).
Portal leans clearly harder on execution.
Portal
Portal placement timing modest.
The Excavation of Hob's Barrow
Pure point-and-click pacing
Same score on reads - which means the number cannot separate them. The difference is in what each one asks of you.
Portal
No adversary modeling player.
The Excavation of Hob's Barrow
No adaptive opponent
The Excavation of Hob's Barrow leans clearly harder on variance.
Portal
Deterministic chambers; no randomness.
The Excavation of Hob's Barrow
Dread comes from unknowns that vanish on replay
Portal leans a little harder on optimization, though the gap is small.
Portal
Pure puzzle-solving optimization.
The Excavation of Hob's Barrow
Linear puzzles with fixed solutions throughout
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.