What is the impact of a change in testimony in support of a motion to change the witness record?

In the instant case the brief statements in the declaration in support of the motion which indicate the connection of the witnesses with the circumstances do not reveal what the substance of their testimony would be and whether it would be favorable or unfavorable to appellants. (See Edwards v. Pierson, supra, 156 Cal.App.2d 72, 75, 318 P.2d 789.) The [202 Cal.App.2d 478] declaration fails to make any adequate showing that the convenience of witnesses, considered in the aggregate, would be promoted by the change. The statements in the appellant's declaration tend to indicate that at least seven of the persons, and possibly more, would testify regarding physical conditions at the scene of the accident. Without more specific information, the court could do little more than speculate as to whether the testimony was unnecessarily cumulative.