Childress' time in Phoenix has been a nightmare. In two year, all he did in very limited minutes was make layups and miss threes. He went 5-40 from three those years. If you take out that horrible experience, he's a lifetime 36% from three, which is acceptable.
Childress is good around the rim, but is a nightmare shooting the ball from mid range. He makes Rondo look like Hondo. If utilized here like AB, running the floor, cutting to the hoop and spotting up for the corner three, he could be effective, but he's no Ray Allen replacement if you're looking for perimeter firepower.