i can see how this language could be confusing, but my point was not that they weren't a theme but rather that being a themed set they were not all that well themed together.
they all even have matching titles.
i just had returned from a road trip, so i put together a set of pictures that dealt with the culture and experiences i had while road tripping.
they were photos from a set of photographs, meant to be together in such a way.
the new photos were taken over a longer period of time and are from various times and places with completely unrelated subject matter and have absolutely nothing to do with one another nor with the photos from the older thread.

how could they have 'roughly the same subject' anymore than drawings of various anthropomorphic characters or what have you have 'roughly the same subject,' and as such basically any thread posted by anyone in art forum should be merged with any other thread posted by that person.
why not merge ALL of my photography, ALL of batty buddy's cartooning, et cetera?

this is just silly. there's absolutely no reason for the two threads to be merged.