Alright lots of people are talking how Khajit would keep up in the Swamps of Black Marsh. How about we turn it around and but these Argonians in Elswyr. The fact that Elswyr is mostly dessert makes it also a dry province. Argonians who live in the province of Black Marsh are used to a more moist air. So they would dry up (not sure of course) in which they would get tired before they could land a deadly strike so in that case I'm sure the Khajit wins.
But in the fight with the imperials, I first of all think both would take them out in seconds. the Argonian would likely use a poison to kill at least one of them and take the rest out in a split second. The Khajit could on the other hand engage in hand to hand combat and take them out with pretty much raw power. But none of you have actually taken account the rocks. Either o the races could make it a hiding spot and lure them and take them out there and when another imperial approaches reposition and use the same tactic.
And I know this is a terrible idea for most of you, but I think the Argonians and Khajit would have a bigger chance of surviving if they actually worked together. Like the Po' Tun and Tang Mo of Akavir. They used to be enemies and the Po' Tun even invaded the Tang Mo but they still worked together. Wha if the Argonians and the Khajit could create a similair pact and fight enemies together, has anyone even thought of how beastly that would be?!