The tariff amounts paid by the south were not exorbitant. In fact the amount of tariff paid in southern ports was a small fraction of the amount paid in northern ports. By contrast, southern exports were protected by the US Navy, and US Army was distributed among southern states in various forts, built by the US government, with localities benefiting from the building of the forts.
“The tariff amounts paid by the south were not exorbitant. In fact the amount of tariff paid in southern ports was a small fraction of the amount paid in northern ports.”
You have it exactly backwards.
The industrial north wasn’t importing manufactured goods, they were producing them. Their industries were protected from lower priced European competition by the tariff. Their wages and profits benefited from the tariff.
The agricultural south purchased its manufactured goods from outside the south. The tariff raised the cost to them of imported European manufactures, or if they bought from the north required them to pay the higher prices that northern industries could command due to the protection rendered by the tariff.
Go try to sell your tariff theory to some libertarians, they’ll give you a lesson in how tariffs work.