The Flybe website would be set up to assume that you are their customer and travelling on their terms and conditions. I agree though that what you're seeing is confusing in the extreme and I appreciate your concern. However you have a document issued by EY stating that your allowance on all sectors is 23kgs and that is what should prevail.
I would suggest emailing your query to EY and printing out their reply in case of a dispute at the airport. It seems that what the EY MAN girl told you is wrong.