That sounds pretty good. However, you have to make a cutscene showing how Guba got out of jail. (since you caught him at the end of CWC) Does he break out himself, or do Spetz Natz break him out?
Also, for mission 3, what is the point of killing the sniper other than taking his rifle? What did he do that caused him to get killed? You should have a mission between two and three, too, since you start on east and then defect to resistance. (unless you just change characters)
Plus, why do you have to re-recruit into the Soviet army under a different name? Is it to gather intel or what? I ask this because in the next mission you just kill more Russians. You should probably describe the purpose of this.
Those are just my suggestions to turn this really good idea into a great campaign.