head to head
Neither is simply harder - they are hard in different places. Blood on the Clocktower demands more reads; Marvel Snap demands more optimization.

Reads · Pure Mind Games
Reading human liars while solving a logic puzzle built on hidden roles.

Reads · Grand Arena
A fast card game where the snap mechanic makes reads central.
Blood on the Clocktower leans Reads (Pure Mind Games); Marvel Snap leans Reads (Grand Arena).
Same score on execution - which means the number cannot separate them. The difference is in what each one asks of you.
Blood on the Clocktower
Talking takes no physical skill
Marvel Snap
No execution component
Blood on the Clocktower leans clearly harder on reads.
Blood on the Clocktower
Detecting human lies and modelling bluffers is the whole game
Marvel Snap
Snap/retreat decisions are pure opponent psychology
Marvel Snap leans a little harder on variance, though the gap is small.
Blood on the Clocktower
Hidden roles and storyteller setup drive every game's information
Marvel Snap
Hidden locations and draws drive swings
Marvel Snap leans clearly harder on optimization.
Blood on the Clocktower
Role interactions and logic chains reward systematic deduction
Marvel Snap
Deck construction and curve still matter
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.