If the name is identical, it should replace it without changing. There could be ways in which the name is recognized as different, especially when dealing with a different volume - the most likely culprit would be if the capitalization is somehow different.
If that's not the case, then I would also try making sure that the document is saved (vs a duplicate/new document), quit, relaunch, and then try the replacement.
Failing that, feel free to send a zip with the .hype document and replacement files to support@tumult.com, along with details about the remote drive (protocol, file system format) and we can look further.