Sorry I keep coming back with all these ridiculous questions.
We're currently trying different ways to import our database from http://www.diabetes.co.uk/diabetes-forum/ to a fresh XF install. First time worked (somewhat) like a charm as we simply merged accounts with duplicate e-mail addresses. The biggest problem with this was that it merged the accounts under the username that was created first. Instead, we wanted them to merge under the username with the most recent activity.
Second time round, we attempted the install without merging duplicates. This threw up a problem during the XF install when it asked us what we wanted to do with the duplicate accounts. Because of the ridiculous amounts of duplicate e-mail addresses in our database, the page was hanging as it tried to load all the duplicates on one page and the browser couldn't cope with it. We left it for ~2hrs to load the page and the browser ended up crashing.
TL;DR - My question is... is there an easier way for us to merge the accounts with duplicate e-mail addresses under the username with the most recent activity?
Thanks in advance for any guidance you can give