They will work it out and I suspect for puppies this young it won't take more than a week or two. Keep in mind they are just like children or even adults--nobody gets along with somebody all the time. They will build a relationship based on their need for companionship and the positive aspects of having a buddy. Your job is only as a referee if things get really rough. Keep in mind even play fighting between two puppies can sound pretty serious. Also be careful not to create things to fight over. I think your lap can be a neutral playing field, shared affection from you is a solid foundation to build on. Each should have access to its own food, toys, bed, etc. even if they don't use it. Within a couple weeks they will be big buddies and probably choose to share. The advantages of having a buddy solves many of the problems that puppies who are alone have to deal with. In my opinion your decision to get two puppies is a great idea.