I think there are many ways you could handle this. If you have the page to redirect to stored on a per user basis then you should be able to store that location in a session variable and use that session variable as the redirect in the authenticate user server behavior.
If you do not have the info setup like this then you could use the same login page for all and store the user access level in a session variable. Then you can redirect to the highest level user page, on this page you can have a rule to check if the user is the highest level access. If they are then they have access to the page, if they are not then you should redirect them to the next highest access level's page. You can continue along until the user is at the correct page for their level.
Another way that you can do this is to have all the users redirect to a routing page that just has some auth rule checks for each of the levels. Each check would send the user to the correct page based on their level. If you can post back with a copy of each access rule that is applied to the pages I can show you more about this setup.
