With 2 parks vs. 4 parks, there are going to be more PhotoPass photographers at WDW than the DLR. That said, I think you're going to find PhotoPass photographers in same general locations at both places.
You'll always find photographers in front of the castle and usually the Partners statue. They almost always have photographers at the established meet and greet areas. Characters just out and about on Main Street, may or may not have photographers with them. You can also find photographers at the end of Town Square facing the castle and oftentimes in front of the Mickey floral.
Likewise, the "iconic" locales of DCA such as Tower of Terror, Paradise Pier and Mickey's Fun Wheel (nighttime also available), in front of the Golden Gate Bridge, Grizzly River Rapids, and other areas along the Hollywood Pictures backlot. And if there is a photographer with a character, take advantage of it. The CMs will take pictures with your camera and the PhotoPass one. I've had instances where my camera had the best picture and instances where the PhotoPass one was better.