User blog comment:IamThorn/Why Glynda is Weak/@comment-121.44.157.206-20141104101130

My assumption was that Glynda wasn't trying to kill Roman and Cinder, merely apprehend them, she used as much force as she thought she needed to bring down the Bullhead without killing the two, so they could be handed over to the authorities. However fighting against Cinder, whose only problem with using a lot of force was that it would draw attention, she was outmatched and they ended up getting away.

However this is just my assumption for her not obliterating them when she had the chance, your theory brings up some interesting points that I had not even considered before. A power limit on potentially dangerous Huntsman and Huntresses makes quite a decent amount of sense.