Another significant difference between the U.S. Marine Corps and their other forces, also might explain why we don‘t have/need marines in Canada.
I learned this past weekend on BMQ from our knowledgable platoon 2IC that the USMC is under the direct control of the U.S. Commander-in-Chief, otherwise known as the President. The other U.S. forces, particularly the army, are under control of Congress, as they are still known by their name in 1776: The Continental Army of Congress.
Under a Republic, the head of state and head of government are the same person (the President), and one of the usual powers reserved for a head of state is actually in the hands of the elected Congress. That power is the authority to declare war. The United States cannot declare war against another power without the consent of Congress. Since the Marines are under direct control of the President, they can be deployed without Congressional authority. That is why the Marines maintain a rapid deployment task force.
In Canada, this is unnecessary. Here, our head of state is The Queen (as represented by the Governor-General, who is the Commander-in-Chief of the Canadian Forces). The head of government is the Prime Minister (the head of Her Majesty‘s Cabinet). Although the head of government must approve of most laws, etc., and is the only authority to raise and levy taxes, etc., the Sovereign retains the power to declare war, and the oath sworn by all armed forces in Canada is to the Queen, Her heirs and successors.
This means, technically and legally, the Canadian Forces are under the control of the "Crown prerogative", should it be exercised, and the Crown has the power to declare war, Parliament does not.
However, keep in mind that we live in a Constitutional Monarchy. The Queen cannot act without the advice of her ministers (Privy Council). Reserved powers are rarely, if ever, used. Functionally, the CF is under control of the government, which has the power to make the laws which affect every other aspect of CF life (who can join, what they get paid, who can give orders, discipline, what kind of weapons we will use, what our role will be, etc.). Since the government pays us, essentially the government controls us. God willing there will never be a case of a government that is not lawfully and democratically elected, in Canada, so that we do not have to test the Crown prerogative in that case (in removing said undemocratic government).
God Save The Queen.