This isn't a matter of being extra cautious. It really is unnecessary, and if you need to translate stamps it's just a needless delay. There is no reason at all to believe that "photocopies of all valid and expired passports" (as it says in the guide) should mean copies of the stamp pages. When people have asked to make copies of my passport, they never photocopy every single page of the passport....the phrasing isn't really that confusing. A "copy of the passport" almost always means the bio page...and even if I agree with you that it's a bit vague, the checklist clarifies the matter.
Not only that, CIC has never required the entire passport for as long as I can remember. They don't care about the stamps because they can be inaccurate and they can be forged. They check with CBSA, and if they're still suspicious, they'll ask for your record of movement from certain countries because that's a solid indicator of your movement as opposed to stamps.