Zach

Not to be that person here but the info on Spartans is incorrect. The Spartan 2 program came after the first spartan project codenamed Orion and both were created to combat human rebels called insurrectionists. The spartan 2s were already deployed and very active when first contact with the covenant happened at harvest.

While the Spartans and UNSC are absolutely dwarfed by the army sizes in 40k, I think the advantage they have is tech and resourcefulness. While the imperium sticks to the same methods of tech and waging war, the UNSC will do anything it can and advance technology to win, as you see with the Infinity adopting covenant and forerunner tech. This combined with actual AI which the imperium will never touch will give them a strategic advantage but will still be weighed down by sheer numbers and power of the imperium.