Cheese and coleslaw is a sandwich defined by a moisture problem it has chosen to take on deliberately. Coleslaw is raw cabbage and carrot bound in a mayonnaise dressing, and it is wet in two separate ways at once: the dressing is a slick emulsion, and the salted raw vegetables keep weeping their own water into it as they sit. Putting that against a slab of Cheddar between two slices of bread means the build is a race against a filling that is actively trying to soak the crumb from the moment it is assembled. Everything good or bad about this sandwich follows from how that race is run.
The craft is defence. The slaw is drained hard before it goes anywhere near bread, pressed in a sieve so the loose dressing and the cabbage liquor come out, because slaw straight from the tub will turn the bottom slice to paste within minutes. The Cheddar is cut as a solid thick slab and laid against the crumb on purpose, doing double duty as flavour and as a waterproof wall between the wet slaw and the bread. Butter spread to the edges finishes the sealing on both faces. The bread is a sturdy plain loaf rather than soft white, because a structural bread can hold a wet, heavy filling for the time it takes to eat where soft white surrenders. It is built to be eaten soon, not made and left, since no amount of draining keeps slaw dry forever.
The slaw slot is where the relatives sit and each manages the water differently. A tighter, drier slaw makes the whole problem smaller; ham added alongside brings salt and a second textural layer; a sharp pickled red cabbage trades creamy moisture for vinegar. Each deserves its own article rather than being crowded in here.