Exchange and EV backup dedupe ratio

Dear Experts,

We have two appliances(5230 with 7.6.0.3) and we are designing what backup data should go where. I am wondering if putting Exchange and EV backups will improove dedupe ratio as both data are email data.

Exchange 2010 and EV 10.0.3 with email and Journal archiving.

Regards,

Gulzar Shaikh