Because the
Safeguard value is the same, having two instances of it has no additional effect.
Smokescreen can’t take more than 3 damage if undamaged. However, if a character has two instances of Safeguard with different values, the lowest value wins. For example, if a character has Safeguard 1 and Safeguard 3, that character can’t take more than 1 damage if undamaged.
Attempting to
Steamroll into an undamaged character with three health, such as Slammer, Combat Drone, and
Safeguard 3 (for example Medic's Protective Field) will first see the damage reduced to 3 damage, and then KO the defender. No additional attack damage would be available to be steamrolled into another enemy.