Oh, Canada!
For expediency have Canada be controlled by the ANZAC player, moving together and sharing a turn, but remaining separate Major Powers in every other way (capitals, treasuries, purchasing and placement, etc.).
Ecan_NBNS.png
CCan.png
norcan.png
Canada_rhs.png
Similar to adding ANZAC, this has the effect of reducing the British paycheck by 5 and adding 3 IPC to the Allies overall… while also shunting it off into a relatively ineffectual power, again due to concentration of force mechanics. Forces (and limits) investment into a particular area, etc.
Need some roundels? Print these on 4x6 photo paper and stick 'em on extra roundels you have lying around:
Canada_Roundels.png