If I am going to be more than a few minutes late for a yoga class I won’t go. Yoga has a flow and focus, and I don’t want to interrupt anyone else.
In regards to the switching teachers, you don’t have to go to just one yoga class. You can always try different teachers, and styles of yoga. Everyone teaches differently, and you will gain something from each different teacher. Don’t be afraid of not keeping up - you aren’t in yoga to impress others, you are there to challenge and improve yourself. You can do it!!
As of these ladies - they sound disrespectful and arrogant. Personally, I would politely pull them aside after class and have a dialogue with them.
You could say, “Girls, I’m not sure if you have something going on just before our classes, but I feel it’s very disruptive when you come in 15 minutes late. I have a great deal of respect for our yoga teacher, and it concerns me that you don’t feel the same way. I’m sure our teacher and the rest of the students would appreciate it if you could make the effort to be punctual instead of interrupting our classes. Please be polite to us and our teacher, and come to class on time.”
Or, if you wanted to be more aggressive/assertive about it, you could smile sweetly and say, “You know girls, it’s really disruptive and disrespetcful to come to class 15 minutes late. Maybe it would be easier for you and our class if you could find a more convenient class time with the same instructor.”
Or, if you wanted to stoop to their level, next time they come in late, get up out of whichever asana you’re in, and say, “Ladies! How nice of you to finally join us! Don’t worry about disrupting everyone and disrespecting our teacher once again, we’re used to it! Roll out your mat, make yourself at home! We can start up again whenever you’re ready.”
Final option? Give them the link to this thread on a card after class. Let them read it themselves and get a hint.