Hey Lum....
airspace over Belgium is controlled by Maastricht, 1 single control
What?
It may be one single control center. Even one single control sector suite. One sector it most certainly is not! The Brussels sectors at Maastricht, as Garp said, are all relatively small by necessity because of the complexity and sheer volume of traffic.
If you can think of a solution in this area, please notify Eurocontrol immediately. You'll be an instant star.