Logically speaking if a file matches one of the filters, it will be deleted. Therefore if you add more filters, you will delete more files. Filters on there own however do little. To give them structure, you have to add criteria. These are displayed as document icons.
Criteria are AND'ed.
This means that all the criteria in a filter must apply for a filter to apply. So if a file does not match all the criteria of a filter is is not deleted by that filter. However, if it matches any filter, it will be deleted. Does a file match ALL the criteria of ANY filter. If yes then delete.