The poll is really impossible to answer because it depends on too many factors, like who has home field advantage.

Sorry, this poll doesn't make any sense. You can't accurately say who would win without knowing more detail. Not to mention in this scenario the likely outcome is alliances would be formed, and there wouldn't be a one victor.

By rusty I assume you mean without the support of all those factors I mentioned.

If no alliances were formed, and if the war started in the current state of affairs(Civil War, Alduin, Weak Empire, etc.), I'd say Hammerfell would win. They kicked the Altmer out of their province with little outside help, just the amount of courage it'd take to do that is amazing. As long as the Aldmeri don't focus all of their forces on Hammerfell, Hammerfell would win.

Well I'm an Argonian soooo...................
Glory to the Argonian empire & black marsh.........

They actually had a lot of help due to the legion General Decianus I think keeping invalids there to defend from Thalmor, although they left after the WGC, and all the Nord legionnaires and Cyrodiil forces killing the main force of Thalmor in Cyrodiil.

The legions that Decianus brought to Cyrodill were Hammerfell legions and they likely comprised of mainly Redguards.

There's no evidence to suggest that. It just says legionaries.

Well the only lower rank solider we know who fought there was Saeel (Lu-ah's husband) Either way the Empire took most of the manpower in Hammerfell away from them so really nobody helped them when they defeated the Thalmor on their own.