Are shield, barrier and armor each completely different, or similar?

I am familiar with this question:

What's the difference between armor, barrier, and shields?

and I understand the use of different ammo types and skills in order to counteract these bonuses. This question is more pertaining to personal character selection. What I want to know is:

If my enemies are using unmodified weapons and ammo, will the same weapon( or skill) do the same amount of damage to all 3 types of defenses? Or will the same melee attack do the same amount of damage?

Another way to say what I'm trying to say specifically is:

The linked post above states, "Slow firing weapons like Sniper Rifles, Heavy Pistols, and Shotguns tend to do better damage to armor." but does that mean the other two types of defenses don't modify that variety of damage at all? Do the other two have a lesser but equal effect, or do all three defenses treat all damage differently?

Like in Mass Effect 2, each individual weapon has different base damage values against Health (Red), Armor (Yellow), Shields (Blue), and Barriers (Purple).

The information linked to in the post is true for the general case - most Pistols deal the most damage to Armor. But you have variance between the individual weapons as well - the Arc Pistol is a pistol that specializes in dealing maximal damage to shields, not armor.

The exact benefit against any given defense depends on the individual weapon. (Melee and the various heavy melee abilities can be considered as weapons in this case)

That clarified, Armor, Shields and Barriers provide absolute protection until they fail (they are effectively a separate health bar), barring special abilities suck as the armor-piercing weapon mods (which allow some damage to 'penetrate' armor), and armor piercing ammo (same).