955 - yet, the court decided to hear the case. It only needed 4 Justices to decide to hear the case and they could've kicked the issue back down to the 9th circuit if they wanted, reasoning SCOTUS will await for a "real" disagreement between the President and an agency-head he wants removed.
So even though there may be agreement among historically adversarial parties in front of the court, the Justices decided to hear the case, regardless.