another way to think about it:
if the script works with different databases etc...looks like they do a different job, and should be separate scripts. Even if they do share a lot of functionality, the common parts can be made modular.
yet another way...
if the jobs are the same, then the virtual hosts (or sub-functions thereof) should become standardized and use same database name etc. if you split up and gave different names to databases just for scalability...there are different ways to approach that problem
sometimes...we need to step back a bit to see a better solution at higher level...just sometimes
cheers, and good luck.