Gs are on the verge of overstrength!
They have one of the best raiders, can counter every strider, have a high range tanky riot/assault, they have two of the best "burst dmg" units. Oh and they have better anti air then air itself.
What more could you ever need?
Unfortunatly I don´t know how to solve the "noob goes gs" problem.
The only thing I often try is to simply tell them to switch.