I got this from IPR and noticed it said "Shuffle the three Major Arcana back into the deck." don't you mean "minor arcana"? The four decks are minor arcana. the major arcana is the other deck, which you'd only draw one of per act. It literally says in how to play "Draw one card from the Major Arcana deck." so you literally can not put away three major arcana at the end of the act because you haven't drawn three major arcana, you drew 3 minor arcana.
Based on a comment from two years ago, I think you have it backwards somehow; pentacles/swords/cups/wands are all minor arcana.