No. Although that approach would at first sight solve the issue, you're forgetting about minor details, such as points. You will have to also update user points of each of them.
Not to mention firing events. If a plugin is keeping track, for instance, of posted questions and creates a summary of posted questions by user, the plugin would, most likely, listen to the q_post event. In this case, the plugin would count the question assigned to the original user and not to the second one.
So it is as simple as you say but the results will be unpredictable, particularly from a plugin perspective.