well the funny thing about the would "could" is it goes for almost everything. We COULD sign LeBron, we COULD change our color to blue next year, we COULD.. well you get the idea. Its really a question of how likely any of these things are to happen. That said, I bet Ainge will try at all of these options (unless he doesn't like one of the guys for the money or doesn't like Cousins attitude in general).
A lot of people said there was no chance we would ever get KG. Like to the point you'd get made fun of for bringing it up. If we don't get good again soon it will be due to bad luck not bad management.