I have written about repeating cards, but the article was about tarot, not playing cards. And for the life of me, I can't remember where that article is published.
No, I don't know of any references regarding playing card groupings, but you could find out more by searching out your questions with tarot as the focus. As I base my interpretations on tarot, you should turn up some answers.
To expand on your question, when two or more cards show up of the same number, then the energy of that number is intensified. For example, fives generally mean that there is a challenge to be faced. Two or more of these shows that there are multiple challenges, and the seeker will be either dealing with them well, or not at all.
When there are sequences of the same suit, it means progression (or lack of) depending on the suit. It's interesting to note that the two 'male' suits Swords/Spades and Wands/Clubs decay, energy-wise, as the numbers increase after five. Cups/Hearts and Coins/Diamonds do the opposite; their energy rises after five. Or you might see them as increasing negativity/positivity. Does that make sense?