I was a bit unclear what I meant with the lesser title, sorry about.
Yeah, those titles have a great impact on the characters they feature, but in regard of the larger Bat-verse, it could be argued that of the current titles Gotham Sirens holds the least importance to the whole mythos, thus the term lesser.
The problem I have here is that the Joker, in turn, is one of the most imporant characters in the Bat-verse and deserves to make his first significant appearance in one of the large titles. Here, to me, it just seems like a complete waste of the character.