Grease bottom and sides of a 9x13-inch baking dish or disposable aluminum pan.
Cut Hawaiian rolls in half. Arrange 24 bottom halves in the baking dish.
Mix melted butter, Dijon mustard, Worcestershire sauce, onion powder, and poppy seeds together in a bowl. Brush 1/2 half the butter mixture over the bottom halves in the baking dish.
Layer pulled pork, ham, Swiss cheese, and 2 pickle chips to each roll, in this order, and cover with tops of rolls. Brush remaining butter mixture over the tops. Cover with aluminum foil and refrigerate for 20 to 30 minutes.
Preheat oven to 350 degrees F (175 degrees C).
Bake sliders in the preheated oven, covered, for 20 minutes. Remove foil and press down the tops of the sliders with a spatula to flatten. Bake until sliders are heated through and top is crispy, about 15 minutes more.