There is an actually used twohander in a museum here that was used in man-to-man combat weighing 6.6 kg (https://greaterancestors.com/grutte-piers-giant-sword/).
Admittedly it belonged to a "giant" at 2.15 m, but it's nonsense that swords don't get that heavy, their usage and role just changes with weight.
Not sure how the name translates, but they were used during i.e. sieges and naval boarding to damage ships and wooden structures.
I've held one in the past and indeed they're extremely unwieldy, but they're sort of meant to be.