"Sine qua non condition" for rules to apply

Hi all!
I'm all new to Hazel and mostly to automation in general. I've read trough most of the manual and looked at some relevant posts without any success in finding an applicable condition/rule.
I've got a watched folder were I'll be downloading three files into every time it's in use. The files will always be an .epub, a mobi & a .zip file. The pdf within the zip file contains the file name that will later be distributed to the .epub & .mobi file. Once this is done the files will be distributed to their specific folder.
With the help of gglick over at the KM forum I got a perfect macro for the distribution of the file name. Combining this with a Hazel rule to firstly unarchive the zip-file before the script runs and later moving the three correctly named files to the desired folder with Hazel was no problem.
Since I don't always want to have to think about in what order I download the mentioned files I'm looking for a "sine qua non condition" at the top that will prevent further rule matching until the watched folder contains all three files mentioned. Without that and if downloading the zip-file first or second my "name giving file" will have been processed and my .epub & .mobi will remain "unnamed" and therefore not get moved.
Any help/guidance would be much appreciated!
I'm all new to Hazel and mostly to automation in general. I've read trough most of the manual and looked at some relevant posts without any success in finding an applicable condition/rule.
I've got a watched folder were I'll be downloading three files into every time it's in use. The files will always be an .epub, a mobi & a .zip file. The pdf within the zip file contains the file name that will later be distributed to the .epub & .mobi file. Once this is done the files will be distributed to their specific folder.
With the help of gglick over at the KM forum I got a perfect macro for the distribution of the file name. Combining this with a Hazel rule to firstly unarchive the zip-file before the script runs and later moving the three correctly named files to the desired folder with Hazel was no problem.
Since I don't always want to have to think about in what order I download the mentioned files I'm looking for a "sine qua non condition" at the top that will prevent further rule matching until the watched folder contains all three files mentioned. Without that and if downloading the zip-file first or second my "name giving file" will have been processed and my .epub & .mobi will remain "unnamed" and therefore not get moved.
Any help/guidance would be much appreciated!