Moreso if Aeris is in control as I can see her keeping the Weapons shut down to give Cloud and co a chance to do things more surgically...

I'm a bit amused at the idea that had they NOT succeeded, it'd pretty much be time to loose the hounds/let WEAPON go after Sephiroth before he did any more with the negative Lifestream.

...Which actually could have been really awesome to watch. Though I'm assuming disastrous for ANYONE in the area, and possibly a large enough area to include Edge, ahaha...