If males, in this case Zuko, have to fight bare-chested, then he wouldn't be able to have any of the same armor that Azula wore because that would cover his chest down to the top of his stomach. That is both not fair for the men and also, that armor is a shoulder garment, since it covers both the chest and shoulders, as shown in the picture, so Azula should have to take it off, as per custom.
Why doesn't she? This seems like another goof of the siblings' attire in Sozin's Comet Part 3, just like Zuko not fighting bare-chested.
Azula_hanging_from_a_cliff.png
Can anyone explain why she wouldn't need to, if this isn't a goof?