Not THAT strong. And if the blood has dried, what caused the stain?
Yes, that strong. How strong do you think it would have to be? Remember, this has been experimentally confirmed.
However, it should also be remembered that the Shroud is not that heavy when weighed per square centimeter. The total weight of the cloth that would have pressed the stiffened hair down is not great.
There is blood that has dried and blood that has clotted and blood that was still seeping from deep wounds as the body was moved into different positions. Experts on blood flow have examined the blood stains on the Shroud and found them quite as expected from the wounds seen.