GF, I pretty much spit all over my computer when you asked if they are rough pups!
Nikki is forever dragging Lupa around by the neck. He just grabs a mouth full of fur and hauls her along. When she manages to free herself from him she gives him almight heck. That's when Halo gets upset. They are very rough with each other, but they don't get the chance to be rough with Halo.