Best practice for FlatFile outbound path using FTP


In my project,I need to communicate with 40 partners.I need to download text FlatFile from a FTP server for inbound and to upload FlatFile to a FTP server for outbound.

Now I am confused about how to set up outbound path.I want to set up process rules to process outbound FlatFiles for each pather and each TN FlatFile type,but if I do like this ,there will be too many process rules about No. of patners * No. of TN FlatFile types in TN.

I want to know how it will influence the performance if too many process rules in TN.And if this solutions is too bad,please give your better solutions.