Need a workaround for a client... other "person" variables in email templates. 

Pipedrive offers quite good email templates. With automations, they're even better. A number of Pipedrive fields (standard/included fields as well as all custom fields) can be used to personalize an outbound email. All good, except... ... except that the only "person" whose data can be included in an email template is the primary contact on a deal. 

For good reasons I can explain, our customers need to include the 2nd (or 3rd/4th) person on the deal. Name, email, phone and a couple of person-custom-fields. 

Pipedrive confirms that cannot include any other-person info to a deal email template. How best, then to accomplish this? Our customers need it! I suspect that the answer is will be an email/marketing automation tool (Cliently, AutopilotHQ, MailChimp or other). 

I hesitate to push our clients this way simply because it adds a whole new layer of complexity to a group that doesn't easily embrace new-tech. Is there another workaround that I am missing?