My older son has some issues that I would call OEs and some that are SPDs and it's very hard to differentiate at times. I think part of it is that it is a continuum like another poster said. For instance, he has always hated to get anything on his hands. I would consider this an SPD. He hates to clean pumpkins, he hates to have mud on them, he hates anything on his hands and he will wash them off immediately. OTOH, he sometimes is very sensitive to smell, however, most of the time smells don't bother him too much, they flare up more when he's stressed. That seems more like an OE.
The problem is that the mix of these make for a kid who acts SPDish. And the sensory issues do sometimes get in the way of his being able to interact appropriately with other people, at which point he needs SPD therapy whether or not he has SPD, just to learn the coping strategies.
