Canada had how many troops in WWII? The British Empire is already represented with UK/ ANZAC / India, and Canadian Roundels.
Other than rah-rahing your own particular country, what major impact would adding Canada as a country provide to Axis & Allies? It would break up the UK’s power even more, (a country that can sorely afford that), and strengthen the Axis.
Or are you suggesting we break up the Axis to include the Germans, Italians, Romanians, Hungarians, etc?
Look, I love Canada as much as anyone else does, and they did provide a lot of support in WWII and WWI, but they are definitely not a major power.
And no, I am not mentally insane.