They should do 3rd place straight to Wembley.
4th plays 7th at home in a one off game.
5th plays 6th at home in a one off game.
highest placed winner of two games plays a one off game at home against the other.
winner of that joins the 3rd placed team at Wembley.
So the teams who finishes 3rd gets a long rest and the biggest advantage.
team who finishes 7th has to win two away games in a row then play a rested 3rd placed team in the final.