So taking a position on the basis of utility rather than on principle?
Nothing wrong with that approach. In 1861 the 13th Amendment would have guaranteed that the Federal Govt. could not interfere with slavery in any state where it was legal. Border States would have supported that.
“South would have then definitely won the war.”
Pure speculation, not supportable by facts.
There is when you try to claim a moral argument for killing people. You claim it's all about some "principle", and then you don't actually take a stand on principle?
Pure speculation, not supportable by facts.
Five more states and all the manpower that went with it? It's not exactly speculation. The South came close to winning anyways. With several more hundred thousand men to throw in it, they very likely would have won.
More likely, with five more states as part of the Confederacy, they would have been seen as more formidable, and this would have greatly reduced the desire to test them.