If two or more replacement effects would apply to a card-drawing event, the player who’s drawing the card chooses what order to apply them. It’s possible that after applying one of them, the others will no longer be applicable because the player would no longer draw a card. For example, if you control more than one Archmage Ascension with six quest counters on it and you would draw a card, each Archmage Ascension’s replacement effect could apply. Once you use one, the rest are no longer applicable.