The whole thing about playing a nation in a game means you support their ideals isn't what I said - I play as Romans, Axis Powers, the Mafia and all sorts of people in games but I don't support what they think. I never said that so...
I haven't researched the Civil War quite as in depth as you probably have due to your mod so I don't really now anything about the intricacies or statistics. It's just that everywhere I search about the Civil War it always said that the whole thing was fought over slavery.
Even in real-life, I would support the confedercy (and as a reenactor, I even have confederate uniforms). But I dont support slavery, like most of the confederate soldiers did not support it (or dont care about it).
When your sources speak about slavery as the main reason, they are no good references to take
I just want to make clear, that the confederate army did not fight to keep slavery (if so, general lee would never lead the army) and many politicians thought, that slavery was not very modern.
There are so many real
reasons, which started the war. But just naming slavery as the main cause, is wrong