That's an incomplete picture. The Russian Civil War was separate from the the North, Siberian, and Southern Interventions by foreign powers. There were four major forces engaged in the Civil War: the Red Army, White Army, Green Army and Mensheviks, and the various partisan separatist movements. Perhaps, yes, if Lenin hadn't faced opposition he would have acted differently, but he did react with brutal violence and oppression. His actions during the Civil War were consistent with his oppression of political rivals going back to at least 1903.