This is a Sonora land map, me as Ports teamed with Germany, vs France and Russia. Randomly 1 good civ + 1 bad civ, it should be fair.
I stayed defensive till a point that enemy's attack slowed down and I quickly beat them up.
* Organ guns no siege power? I don't even have an artillery.
* Cassadores ain't effective? I haven't trained one.
* Dragoons and muskets are late game? Sorry, I don't know what you're talking about! With them I can't survive Fortress.
See how I sieged a fort while defending. Church techs >> guerreiro muskets or jinete dragoons.
But why Ports?
I don't know then.
Perhaps multiple TC's avoid economy pause under attacks?