i think that you should call your child the name that you want them to be called. i wouldn't bother with longer names- particularly if it's one you don't really like. it just causes confusion.
Lottie is a great name- if it what you really want, then just go for it!
our ds2 is named Jimmy- not James, just Jimmy...and we love it. it suits him perfectly. he's not a James and it would've annoyed me if people called him James, so i'm glad we stuck to our guns with the name 'we' wanted him to be called.