Armored melee combat differs, true!
But, as fencers typically we do not aim to simulate melee combat in armor. Rather, we wear protective gear for safe fencing.
And 1v1 (‘duel’) is a bit different from ambush or battlefield contexts
heres a little fact, Melee combat is never like this, you never get to kill your opponent in singular blows, even on duels. your armor usually protects you good enough. and you'd have to make strong blows to take down your opponent untill he dies.