The Atlanta Hawks, the best analogy for them, they’re the chick on the side, never given the chance to be girlfriend number 1. The Hawks are consistently 4th or 5th seeds in the East but are never thought to be title contenders.
A roster with their two best players being really good, no one is going to assume Josh Smith and Al Horford are the players to take you to the promise land.
Adding Lou Williams and Kyle Korver will help with the scoring you lose from the loss of Joe Johnson; however they’ll probably be nothing more than at 6th or 7th seed. Unless they can find a way to get a superstar, I don’t see the fortunes of the Hawks changing anytime soon.