The bigger problem for some lawyers, especially litigators, is a psychological one. This is a perfectly understandable feeling. Frankly, we don't expect litigators to be the first to adopt this form of practice, unless their clients demand it. All lawyers have been schooled in the adversarial tradition. Trial lawyers have made it their stock in trade.
Collaboration is a different way of approaching a dispute.
It views a dispute as a problem to be solved rather than a case to be won. It calls for a significantly different set of skills, which is why collaborative lawyers here receive two full days of training, mostly in interest-based negotiation and collaborative communication styles. The transition from adversarial litigator to collaborative problem solver is not easy for everyone. After all, I negotiate settlements for my clients in the great majority of cases. Very often, it's the threat of litigation that brings recalcitrant parties to the bargaining table.