Zant is not as cowardly as Ravio. And the Twilight Realm doesn't have the same "doppleganger" effect that Lorule and Termina do.
There is something to be said for the people of Lorule to be practitioners of similar dark magic to those in the Twilight Realm, potentially leading to their banishment. This brings in a larger question of what magic is used by who in the Zelda series: Lorule seems to be connected to the same rainbow magic as Majora uses to form its body, and that is dispersed upon its death. Twilight magic is a cyan, green-ish color, a similar color used by wind magic practitioners, such as the Gust Jar and the robots in Skyward Sword, who have the Wind Crest from the Wind Tribe from The Minish Cap on their foreheads. This brings in the idea that Farore is the Goddess of Courage (Link) and Anti-Courage (Ravio), Forest (Saria), Wind (Fado and Makar), and maybe even Time. Then maybe Zant uses corrupted wind magic like Ravio is a corrupted wielder of the anti-ToC? That's my best guess; the dimensions don't line up with other theories.