Indeed, and who needs an 'artisan' crisp sandwich. Cheap crisps is better.
I'm not a complete gastronoramus, I don't mind wholemeal bread, but it has to be medium or thin or the soft to hard carb ratio goes askew and no one wants that.
As for pies in sandwiches, keep up at the back, that's the Jesus Sandwich. Triple decker, pie on the bottom deck, chips on top. Generally there should be gravy enough the pie, but I understand northerners don't consider it enough gravy unless there's enough to fill a bath. If you're concerned there's not enough veg in your diet, it's completely permissible to add mushy peas to the top deck. Trust me, this is documented in the Bible, admittedly in one of the lesser-known Apocrypha.
I've never had a mashed potato sandwich. I'm not sure that would work, the beauty of a crisp sandwich is the contrasting but strangely complementary textures.