You might be able to avoid overlapping e. g. if its two approximately round objects, by using distance, if its two boxes, by the coordinates combined with the sizes. Unnatural20 If you want to spare collision checking that is, which might be very much a reason to avoid that condition.
So obviously, if you already check once for overlapping/collision, put it in there. If you can avoid that for performance, you should. Also note, that every time you repeat "if overlapping" or "on collision" the system actually tests each and every time. It is best to test every possible collision you need just once.