Do two copies of the same ability stack on one unit, such as two Strong sources, two Hellforged Weapons or two Deceivers?

Question

Accepted Answer

Not when a unit gains the same named ability twice. A unit can have a named ability only once, so two Strong sources do not add dice and Cursed from two Hellforged Weapons applies once, though their strength bonuses add. Abilities that belong to different cards on the battlefield do stack: two adjacent Deceivers each apply Stupefy, so the attack deals 2 less damage.

Summoner Wars (Second Edition)

Do two copies of the same ability stack on one unit, such as two Strong sources, two Hellforged Weapons or two Deceivers?