Looking to have my cake and eat it too.

I have alot of users that have been using Winbind for years. They currently log in with the workgroup, ie:

WORKGROUP+username

I would like to roll out SSSD with the ad provider. I would ideally like for a user to be able to log in as:

WORKGROUP+username

or 

username

and sssd would know this is the same AD user.

Is this possible?

thx