I think you may have misread the fourth rule - we are told that there is exactly one spot between M and P whether or not M is earlier than P. We are NOT told that M is always earlier than P.
Therefore, P could perform before M and could go in the first spot. Parker does not have to be last.
From the spacing in which the rules are written, it could be easy to mistake the last line of the fourth rule as its own rule. To prevent this, I would recommend paying attention to sentences as opposed to lines. You may also want to check to make sure that you have written each rule correctly- it is worth it to spend a little extra time upfront to make sure you have the right setup for the game.
Does that make sense? Please let us know if you have any other questions and best of luck with your studies!
