Divorcing spouses should never, ever be represented by the same lawyer under any circumstances. There are a number of options available for couples that have decided to end their marriages, and it is indeed possible to save time and money, but having one lawyer for both parties is not one of them. The one thing we tell everyone loudly and clearly is that having one lawyer represent both you and your spouse is a recipe for disaster, and is in fact, impermissible according the Arizona Rules governing the ethical behavior of attorneys.
The most prevalent option is litigation, in which the spouses and their lawyers go to court where a judge will ultimately determine the issues like custody, support and property. It can exact a very costly and painful toll.
Another option however, is mediation, which allows a third party (like a family-law attorney, or a therapist -- if custody is involved) to privately work on a binding resolution to resolve the issues and arrive at a final agreement that will be endorsed by a judge. Mediation is a fabulous way to avoid serious financial burdens and many months of depositions and court appearances. But, as always, there are pros and cons to using mediation.
The bottom line is never to allow a spouse to persuade you that a divorce can be equitably handled by sharing one attorney. Both of you will come out losers.