I disagree that Gag Order needs a buff. Maybe a Reduction to 2, but certainly not 1.
Sleep is removed as soon as you do anything to the target, making it only significant for a final round move. Even then, if the A.I. wakes them up with some A.O.E., they may still just go in and attack.
While Silence will persist, and is particularly useful on annoying mages.
If you're using these moves solely as magic armor strippers, yeah, Gag Order will seem weak. But there may definitely be tactical times when that silence easily outpowers that sleep.