No, because the stamps would not prove residency. Besides, why would the have a stamp in their passport if the entered Canada as a PR?
Send a couple of bank statements (find ones that show actual `active' activity in Canada (local ATM, merchant, restaurant, etc.) rather than an online purchase. Since you need at least 2, from Appendix A, maybe a copy of their DL, or a membership card somewhere?
If they ever left Canada within the last 5 years, they hopefully have records of their exit/entry dates, because they need them on the application. If they do NOT have the info, they should request a copy of their CBSA travel history via an ATIP request through CBSA. Yes, the application asks for consent for IRCC to get info from CBSA, but the applicant still needs to populate the application with each and every trip first...even a trip across the border to get gas and return.