Working in an IT environment where I manage keyfobs on a day-to-day basis (swapped over roughly 450 last month), I know it's possible for a user to have two or more different tokens displaying different numbers which all work. However, what I don't know is what kind of licencing system SE have. With some licensing systems, you can only have a set number of users that have more than one token and those users are generally admin accounts rather than end users.