How Should HR and Training Managers Resolve Their Standoff Over Training Methods?

The HR Manger and Training & Development Manager of "Orient Associates" has a conflict on the mode of upcoming training program for their engineers. Both the managers are strict to their own stances and none of them are willing to accept other's point of view. Conflict is going to prolong and intense. Other colleagues are convincing them to solve the issue cooperatively and in a friendly manner.
What would you suggest that how this conflict should be resolved?

It seems when two elephants fight, the grass suffers. A good mediator should be able to alleviate the problem. In most cases, both would have good reasons for their stance, but neither listens. Check it out.