That does sound bad.
I'm sort of surprised that teams would go all in on sign stealing, in that they change signs. One finger isn't always a fastball. Of course, they probably have hours of tape on every pitcher in every situation that is distilled through the advanced stat computer god and it spits out, "here comes a fastball".
I've also heard players say they don't want to know (maybe they're lying).
Also, sort of interesting that Verlander is pretty vocal about not cheating (drug wise anyway).
They probably take the first inning or so to figure out what sign in the sequence is the correct one. After that, idk that it gets changed much. Or if certain pitchers have preference, like you said, there will be plenty of tape.
Yeah and Verlander was bitching about the balls too.
There have been a lot of rumors. This is damning coming from a player that was there.