Every position will have different sensible limits, which will differ for each individal and weather conditions and complexity on the day. I doubt that an individual can give undivided attention to more than 10 different flights doing different things, but procedures can be in place to simplify things so that you are not controlling individual flights so much as working a system.
You can have 40ish in the ATZ and further traffic joining without holding them off, but there is no way you could control each flight individually as there is not sufficient RTF time.
Last edited by Dan Dare; 27th Nov 2012 at 15:45.