One of the reasons this plot doesn't make any sense is that even if Dick thinks Gotham needs a "Bruce Wayne" there is no way it should be Tommy Elliot. It was just awhile ago he cut out Catwoman's heart (and Zatanna was part of that storyline for goodness sake), in addition to all the other sick things he's done. He's a medical genius who's thrown everything away just to pursue a childish vendetta against Bruce Wayne even to the extent of looking like him and giving away his fortune. And Bruce's friends are COOL WITH THAT? As long as he runs it by Wayne Execs?
Even if Zatanna had a moral problem making someone else look like Bruce Wayne couldn't she go "Erotser Samoht Toille Ecaf" and end this farce. After mindwiping him, apologizing with promises to make it up to him (in JLA) and being quasi-in-love with him, one would think Zee would be the first to volunteer to avenge Bruce.