There's absolutely no downside to pursuing them. Also some people are acting as if you can only pursue one group of free agents at a time, we can gauge interest from dozens of guys at the same time. If Gasol and Aldridge turn you down, which is likely, it doesn't matter because you are in no different a position as you would be if you didn't throw your hat in the ring.
It's like someone offering you a free lottery ticket, you probably won't win but there's no reason not to take it.
My argument was with those who said it wasn't possible because we wouldn't have the cap space, which we could get by only giving up Mills, Joseph and fringe players.