If all they do is resign Moore it's akin to a .500 record version of tanking they might as well kept Rose and waited until next year.
If Barnes makes a leap to be a strong second option then it becomes a great move to sign him. If he's about where he is now for the amount of money he is expected to get, they would have thrown away much of their chances. If you rate players 1-10 when you're going to sign FAs for big money you want to step up from the players you already have from a 4 to a 7 or 8. It doesn't make sense to sign a 7 if the guy you've got is a 6. I just think signing Barnes means they have to trade McDermott because he's not worth having if he doesn't get playing time to improve, he's a #7 pick trade him for some undrafted guy who doesn't take up cap space.
Looking at the players in the article I'd be more interested in someone like Mo Harkless, Alan Crabbe who might, like Barnes, be players who you hope haven't reached as high as the team that drafted them thought but make a big improvement when they got to their second team.
I really have no interest in guys like Mayo, Turner, Jones, Gordon, Stephenson, Hairston Williams who have kicked around to several teams and still aren't becoming front line players. They would do just as well to not sign anybody and sit on the cap space.