Sure, it can be taken as given if you want lazy writing focused purely on plot devices, MacGuffins, and Mary Sues. But I like deeper fiction. We've seen the Predacons be tough going all the way back to the Costa days. For them to be hypnotized off-screen is absurd. I also don't think we've seen in-fiction (at least in the TF-prominent books--LL, OP, Revolution, Revolutionaries, or Rom vs. TF) claims that Rom is the greatest of the Space Knights.