Ratio of certificates for SharePoint 2013 SSL offloading

What is the best ratio I can achieve in regards to virtual servers providing FQDN route to several farms (e.g. production vs. qa). Assume SharePoint is not configured with Request Management servers between LTM and WFEs. Having read several SNI solutions documents, I realize there will be 1 HTTPS profile per certificate and multiple HTTPS profiles can be configured on the same virtual server.