Regarding the Gladius and Mail

[Dan Howard]

Mail can't be penetrated with a one-handed weapon unless there is a flaw in the armour. Specialised swords such as "tucks" were developed to get through armour and they had to get rid of the edge completely. It was essentially a long round-sectioned spike and wielded in two hands like a crowbar. Another armour-piercing weapon was the rondel dagger, which was a short spike with a disc on the back to enable the second hand to add additional force. The best tactic was to get the opponent on the ground and fall on him with the dagger so your body weight adds to the impact. The best armour piercers are all used in two hands, ideally with the target being incapacitated on the ground first.

Bodkins were not armour-piercers; they were used on long-range arrows. The compact broadhead was the armour-piercer and it had to be shot from the heaviest bows at the closest ranges (delivering more energy than is possible with a one-handed thrust) to have a chance of penetrating.