Just to make the question more clear.
It is easy to see how many instances is open but when you have many of them, each one with a different maximum it is to easy to see witch one does not have max instances big enough.
If you are ok with doing an average of your ArcSOCs you can try using the process counter that comes out of the box with ArcGIS Monitor.
What about running the ArcSOC Optimizer in list mode? This will generate the report but it does not change the min and max instance settings, so you get to review the report and decide what changes to make.