It is true that smart is a player that would help them on defense, and on offense they have enough players so they do not need another offensive guy. They already have what they need and because of that they should not really focus on whatever they lack, and that is defense. If they could also get a decent big, who can grab boards and protect inside, then they are going to be contenders for sure.
However, so far they are not doing that great on that part, and that is going to cost them a ton. Hayes isn't enough, they need someone who is much better there, I am not saying go get AD back, but they need someone who could be good enough and be playoff level player at least, otherwise they are not going to get any good results.