Aren't they simply replacing the card of the same number?
E.g. EXP-8 for the Greeks (Ophellas) replaces 8 - Agathocles lands in Africa?
Yes to the above quote, I believe there are 6 cards that have to be swapped out. If you go to the GMT Games webpage, "Sword of Rome" page, there is an excellent .xls doc there that you can d/l that is a card manifest, it tells you all of the cards that need to be exchanged between 5p and 4p...I refer to this doc frequently.