Content rule for mailing 'with attachments'

I have been asked to make a Content Rule that mails (170+) users and includes an attachment (word doc).

Is this a 'bad idea' (my approach/suggestion would be/is: include the link so the users could download the word document instead)

word/doc as portable document format is a bad idea

Customer insisted, so I 'added it'.

Basically, I added a 'bool' field in the schema (include attachement), and checked if the item had a file and included it.

Question: Is it possible to 'add this to / 'patch' the current mail content rule', or do I need to make a new content rule and hide the default 'send email' rule?