The armour worn by the combatants means that cutting attacks will be largely ineffective. Also, short of holding the sword by the blade, effectively transforming it into a pollaxe, like the 6th guard, the sword lacks much scope to deliver percussive attacks.
Sword in armour techniques are delivered from a half swording grip. Entering as quickly as possible into narrow play, the fight progresses with plenty of grappling.
The mass of the sword and the double handed grip provides the opportunity to seek out very specific target areas at gaps or weak points in the armour and push the point through. The double handed grip also serves to give excellent leverage for pommel strikes and using the swords cross bars as piercing points. The extension of the pommel and the point beyond the hands are used as hooks to assist with throwing your opponent to the ground.
A good understanding of abrizare and the Sword in Two Hands – Narrow play will serve you well here.