Arguable. Anyone wearing mail or plate armour would actually receive MORE damage from a blunt force attack than a blade, given the way such armours resist and deflect cuts.
No, because not all blunt weapons are the same. Blunt weapons specifically designed as a counter to armor are more effective than blades that aren't. But there are blade weapons, such as pole axes or halberds, designed with armor piercing in mind that are just as effective against armor.
The shaft of a greataxe is just a stick and the flat side of the axe is just a paddle. Neither of these have any efficiency when it comes to damaging someone in armor. You are better of striking with the blade even if the armor will deflect some of the force because at least the force is more concentrated.
