Congrats on your doula program!
One of the ways my collective has solved this problem is by spending more time educating and training the birth partner (dad, mother, whoever who will support mama). That limits the amount of time our doulas spend at the birth, and also has created newer doulas. A part of our philosophy is that we must all learn together, and teach all that we know to our community. Although some of the newer doulas have not undergone certification, they are available to attend births of friends and community members- all of whom have good things to say.
I'm going to write a little more details about it in my blog. Let me know if you want the link.