Spartans are super soldiers.... Guardians may have a chance/edge with their Specials against a Spartan... But I know most real Spartans were beefed up to be a Super Soldier, which is why they can flip a tank like a paper air plane... It's a tough call, In a fist fight, Guardians won't stand a chance against a Spartan, gun fights, it's a tough call to say, Guardians have more weapon choices, where as Spartans don't have a huge range of weapons to choose from... Anyways as much as I love Halo and Spartans, I will have to say Guardians got a smaller edge with their unique abilities (soon to be Titan Fire Mjolnir and Warlocks Sith Lord specials) where as Spartans don't seem to do that or have a variety of weapons to choose from...