Sascha Noyes wrote:
The only problem with the merge is the collision of accounts (eg. there exists a [[de:Jan]] and [[en:Jan]], but they are not the same person). Your proposal does not solve this, but would need to solve it in the same way as the simple merge would: In the rare cases that this happens, people need to discuss and come to an amicable sollution. (I would suggest that whoever registered that account name first should have priority.)
Since the en:Wikipedia is longer with us, fist-come-first-serve would favor Accounts from en, possibly causing some unhappyness, but it's the most straightforward solution. Ambiguous accounts could be simply numbered (jan1, jan2). Very nice would be a feature to rename the (own) account resp. the ability for admins to do this.
In any case the editing history and the signatures on talk pages etc. have to be synchronized with these changes; this could be either done by a bot, but it would be non trivial (when is the account on which Wikimedia site being changed, when does the bot start renaming, when does it finish, when can the account be used again) and cause much load, if many accounts have to be merged, or (probably preferred) by direct database manipulations when the database is read-only until all changes are completed and the integrity is verified somehow. Or is there a simpler way?
Regards, -asb