Here's the thing about medieval weaponry: there wasn't a huge emphasis on uniformity. While there were some formal/legal requirements depending on rank and station (archers would have to bring a bow) , decisions about individual equipment were left to the individual/whoever equipped an individual soldier. So while all men-at-arms would be required to show up for battle with a minimum of equipment (armor, sword, horses, etc.), the king would not be rejecting soldiers for bringing a polearm with the wrong kind of pointy thing at the top. Obviously, a fifteen foot pike would not be considered an appropriate weapon for a heavy infantryman to be using in the melee. But aside from obvious practical concerns like that, a man-at-arms would be equipping himself according to his own needs and experiences. Our modern concern with specific names of weapons wasn't such a big deal to the medieval warrior. A man-at-arms- and medieval warriors as a whole- would be trained to use multiple kinds of weapons and would switch between them as the situation warranted. He was much less concerned than modern armies with a need for intricate categorization and the desire for technical specifications.

Pretty much all of our sources indicate that there were a huge variety of arms present on the medieval battlefield. One source mentions "swords, hatchets, mallets, axes, falcon beaks, and other weapons" being wielded in close quarters. For a dismounted man-at-arms specifically, the most likely individual choice would be a poleaxe: wielded two-handed without a shield. Pretty much all men-at-arms would also have a sword and dagger belted at their sides. Another common choice would be the cavalry lance. Remember, dismounted men-at-arms would still have brought horses to the fight and would sometimes remount if the situation called for it. For dismounted fighting, men-at-arms would sometimes cut down their lances to a more practical length for infantry combat.

Tactically speaking, the purpose of dismounted men-at-arms was the bear the brunt of the enemy's attack. In an ideal situation, the enemy would be forced to attack, harried by flanking archers in the advance, and then be engaged by the main force of heavy infantry while disordered and tired from their advance. The English men-at-arms would then chew through the front ranks of the enemy, while their archers would come in from all sides to surround the enemy and rout them from the field.