Long form or short form ads on FB?

Hi Coaches! Thank you in advance for your help. I started working with an ad agency that helps coaches market their courses on line. Today they presented us the first three sample ad and copy to run. They were all LONG. I why so long and they shared they find they do better than short in attracting the “right” client. Of course they said they can test short, but they find long form ad to be the way to go. What do you find in your guidance of coaches and in you own ads you run for Brooke and The Life Coaching School? Thanks!