Fun fact, rooted or not - you can backup your Contacts on Google from your PC.
Go to Gmail, click the red Gmail in the upper left, choose Contacts. To the right of that, More (dropdown), Export... and it will save a contacts payload to your PC.
I like the vCard format, it's a standard. They also have csv file backups, I've not tried those lately but in the past, I didn't have great luck with them.
Anyway, if you bork any part of your contact list, you can use that backup to restore using the same path, choosing Import... From there, follow your nose and have it remove all duplicates.
Because, yeah, in the course of trying to keep my contacts sync'd I've managed to sync some of them into the ground.
So, there you go.