I had a homebirth with 2 midwives (my midwife and her partner) and THREE student midwives, plus our birth photographer.
I agree, it's your right to choose, especially if your midwife gives you the option, but my midife never did -- she is one of the only CPMs in our state who takes on apprentices and it is never even offered as a choice, it's clear from the get-go that her students are integral to her practice. And I think both client and midwives benefit.
Whoa - OK, I can understand that it's a requirement that a MW have a student with her - and maybe even another midwife AND a student for a total of 3... but does she really not let you have any choice in the matter when it comes to having a birth team of FIVE??? Sure, some mamas don't mind and I'm glad it was so positive for you, but if I had to have a birth team of 5, NO WAY would I go with that MW. Even my hospital-based midwives were respectful of my desire to have a smaller birth team & said it was fine to have only a MW and a nurse in the room.
& I'm pretty sure a lot of mamas would have a problem with a birth team that large, so it would really surprise me if she didn't let any mamas limit the birth team to a max of 3, or at least a max of 4 if they desired.