As a pup trainer, I have made the choice to create a pack and train multiple pups simultaneously. Not for ego, not because it might seem easier to the uninitiated, but because it serves my own purposes. and the pups well. Let me explain it in detail.
I see that many relationships in pup play in the BDSM community are deep and affectionate, a bond between pups and owner that is enriching and fulfilling. I love my doberman Khan with a strong bond, and I feel such a bond for my pups. However, I don't want any of my pups becoming too attached to me - too attached is the key phrase here. Despite some healthy pup/owner relationships out there serving as examples, a good number of potential pups seek to have an intimate, and often slave oriented, relationship with an owner. I don't want that. I already have a servant, and I have a husbear who loves and adores me. I don't need a submissive craving my attention. That kind of dog may suit another master, and I hope that each and every one of these sub slave pups find the right owner/handler for them. But that level of attachment is not what I want or need.
The bond between myself and my pups, and the bond between them is complex, not easily reduced to simple terms. Like any sincere relationship. We find it hard to define our roles as sons, parents, partners, friends. No motivational poster proverb is going to summarise the relating between me and my pack easily. I still have to answer why a pack though.
A pack allows every pup to be a brother, to be supportive and guiding to the other pup, and to have someone to play and have fun with. The pack also allows me as an owner to focus on the role of trainer and handler, and avoid becoming too emotionally focused on a sole pup. We all love being looked up to and adored, which pups do to their owners. My own practice is to avoid the lure of egoism and veneration, and to strive to be an living human example, not a fantasy paragon. I find that it is important to me to create a circle of respect and care and love between pup and trainer and other pup. The pack is above one pup, and most certainly more than just me, the owner. It is a place of spirit we can all share in and belong to, enjoying a hobby, a fetish, a way of expressing ourselves, in safety and security and in support of one another.