I am student, wife is clergy. Under which provision should she apply?

I am about to begin a Ph.D. program at U Toronto. I have applied for and received a letter of approval for a student visa, which I will receive upon entry to Canada. My wife is ordained clergy in the US. Her credentials have been reviewed and approved by the United Church of Canada for her to serve. She is beginning to interview with churches in the GTA.

As I understand it, she could follow one of two paths: 1) Under R186(l) she could avoid having a work permit altogether. She will be forming clergy duties as outlined CIC documents; or 2) She could, as the spouse of a student, apply for an open work permit which would then allow her to seek work without a letter of offer.

Is there any particular advantage to her or to our family for her to pursue one status over the other? Thanks in advance for your help!