I can't answer what historians consider, but I can note that the "1867 Canadian constitution" didn't really contain an analogue to the U.S. Bill of Rights. The Canadian Charter of Rights and Freedoms took effect in 1982. As such, the freedoms and rights enunciated in it are more aligned with modern perspectives (for example, it concretely prohibits gender discrimination). But to compare the two beyond the historical perspective is folly. The analysis doesn't really fit your parameters. It's like comparing the Magna Carta with the U.S. Bill of Rights.

One difference between the two original documents is that the US Constitution has residual powers going to the states, whereas Canada has them residing with the Federal government and not the provinces. That’s not really a conservative /liberal concept, though modern movements tend to see "state's rights" advocated more strongly by conservatives.