Many language schools use 'standardised' programmes in order to achieve quality control, which means that they trust the content of their programme over the teaching ability of their trainers. Trainers essentially become facilitators of a 'one-size-fits-all' programme.
Having been trained as a professional teacher, I understand what teaching really means, which is tailoring the content to meet the needs of the learner rather than the needs or convenience of the trainer. So, I employ good teachers and trust them - require them - to use their professional judgement about the speed and methods with which they train their customers.
The most valuable resource in our institute are the trainers themselves and I trust them as professionals to do their job.
This is something customers not only instinctively understand but also expect.