Barely melted blue cheese over barely toasted bread doesn't appear be very appetising or croque to me but hey you clearly know what you like. However your assumption that there are no rules just personal preference is of course utter nonsense, there are culinary rules or flavour profiles that work well or better together (that we have discussed) that either you're not aware of or don't comprehend or appreciate, in fact some cuisines are entirely based on balancing them.
Oh by the way your bread may have been born in the nineteenth century but like most industrially produced sliced dough it grew up in Chorleywood circa 1960.