I have now altered the wording in the OP and points scoring so that it complies with the way scoring has been in recent years. There was a flaw in the the way it was presented so getting 6 points was impossible, but I have now corrected that.
The rule now reads:
Extra point: If your chosen regular scorer scores the first goal, then your second candidate (dark horse) becomes available for the second goal of the game for a maximum of 4 additional points (scorer + correct play). Thus, the maximum number of points in one game is 6.