If serving immediately, preheat oven to 350 degrees.
Cut each Swiss cheese slice into quarters. Set aside.
Keeping rolls in single sheets, using a long serrated bread knife, slice rolls in half from side to side. Keep sheets intact as much as possible. Spread cut side of each half sheet of rolls with the 2 sticks of softened butter total. Toast sheets, butter side down, in non-stick pan until cut side is golden brown and crunchy. Set roll sheets aside.
In a small bowl, mix together mayonnaise, Miracle Whip and garlic powder. Spread mixture on both cut sides of each roll sheet (top and bottom halves). Keeping the rolls in sheets enables this to go much quicker. Divide ham between sandwiches and place 2 quarters of of Swiss cheese on top of ham on each roll section. Cover rolls with roll tops and place them in the baking pan.
Sandwiches can be assembled with out drizzling on the dressing, wrapped well with plastic wrap and refrigerated up to 24 hours or frozen, wrapped will with plastic wrap and then aluminum foil for up to 2 weeks. Defrost several hours in the refrigerator. In either case, don't add the drizzle before refrigerating or freezing. Dressing can be made in advance and refrigerated separately up to 2 days.