Here's Deja Vu, the second Soviet mission from Yuri's Revenge, where you get to destroy the Chronosphere prototype (already built into the Chrono Miners, though). I won't even get that far to compare the tech used by the Allies with the one in the original Red Alert, but I've still got a question, though... How the hell Prism Towers got in there? I mean, even knowing how genial he is, Einstein wouldn't invent the Prism technology until he's done with the Chronosphere! Not to mention that, yes, he presents the said technology in the unexpanded Red Alert 2 to the player in person, as well as the ready-to-use Towers, but that's not until the fifth Allied mission. And Deja Vu takes (or may take) place just a bit after the First Soviet Occupation. And the Towers in this mission function just as their "official" RA2 counterparts.
I think you might be confused. In the stand alone game the Allied mission is to defend Einstein from the Soviets. Deja Vu is the same mission, except you are the Soviet forces. As for Einstein and his prism technology, given the Soviet threat this might be something he had kicking around and he was able to put into a weapon.