There’s no substitute for decision makers being present at the mediation. Of course cases often do settle when defendant insurers are absent, represented only by solicitors (an increasing trend), but there are occasions when settlement on the day is a step too far. In such cases, the mediation is often adjourned while insurers are consulted and further negotiations follow.
In my experience (and I can think of two such cases within the space of two weeks) claimants then generally harden their stance and settlement becomes more expensive than the deal that I know could have been struck on the day.
So, persuade the decision makers to attend! It’s in their interests.