Why would those be contradictory? If the prosecution charges a person with X, and the maximum penality for X is, say, 10 years then it seems perfectly reasonabl

Why would those be contradictory? If the prosecution charges a person with X, and the maximum penality for X is, say, 10 years then it seems perfectly reasonable to say that this person faces up to 10 years in prison. In court the prosecution may well argue for, say, a 5 year penality under the given circumstances, and ultimately it's up to the judge.