since you mention a ‘studio’, I assume that we are talking about a rather small space with only a handful of instructors.
In a small environment like this, it should be possible to track who is attending which class, and you will probably soon find that the same people tend to gravitate towards the same instructors. The more limited the number of instructors, the more you will be dependent on those that draw participants to their classes. This is even more relevant in yoga practice where you have different yoga styles in addition to the different teaching styles of the instructors.
Having a teacher who draws participation is a great asset because you can use her as a mentor for other instructors, and over time the participants would be willing to accept them as well.
I like Ariadne’s comment about spending more on teachers’ pay than on candles and pillows.