I would recommend to send a DSAG member or have the Instructor that will go for training to become a DSAG member afterward.
Due to SMS training, according to our manual is done by DSAG of their department. And inorder for instructor to teach SMS it will be benifit for he/she to be a part of the systems. (In SMS systems, Training is one of the Safety Promotions)
And also it will benifit the company to use the knowledged of the person that has been trained.