Do you mean confusing as far as pruning? I'm not sure about Smoke bush, but Buddleia is best cut back in spring. I actually prefer to cut mine way back, to about 12". Our winters used to be such that butterfly bushes were regularly killed back to the roots anyway, but the last several years that's not been the case. But I've still found that they have a prettier shape if I go ahead and cut them all the way back. One year I experimented, leaving 1 and cutting the others back, and they both started blooming at about the same time.