Sometimes writers like to use the fact that these characters exist in the same universe, and pull other people's villains in. Giganta and Angle Man are primarily Wonder Woman foes, for example, but they're usually in some other book.
It should also be noted that this was during Deathstroke's antihero phase that Wolfman started over in Titans. That lasted as long as Wolfman's Titans was still going and popular.
I'd have liked to have seen how Perez would have done WW vs Ivy, since, with Karen Berger editing, it would have been Gaiman's take on Ivy, the insane May Queen with a mystical connection to the Earth Mother (that Rucha would play up during No Man's Land). Given that Perez's Diana also had a special mystical connection to the Earth Mother (I'll have to figure out how to edit that story with Gaea and Pandora to fit the posting limits), it would have been an interesting conflict. So many What Ifs when we speculate on where Perez and Berger would have taken Diana if they'd kept the character...