I think it is really cute and I would probably do something like that too... to tie them together put give them a little of their own identity.
although... I went to high school with these twins named Gynn (
Gwen) and
Lynn and they HATED it. They said that everyone knew they were twins anyway... why did their name have to scream it as well.
even still... I would probably do something cheesy to my kids if I had twins.