That's not what the multi-player campaign is like. The way it was explained to the community months ago (check the RO Facts thread), unless something has changed, it's like a short version of Iron Crescendo / Battle for Europe. Essentially, you have two teams fighting over territories in Stalingrad, like the board-game Risk. When you win a battle over a map, you gain or hold that territory. If you loose, you loose that territory (or don't advance if you attacked).
How you did in the battle will also affect how much "war power" you have for either defense or offense. You may play all day to ultimately win or loose the city.
It sounds like a lot of fun. My only concern is we'll probably get sick of the maps in the middle of the city, as they'll be played the most. Maybe having a mode where you have to battle back from the brink (with fresh reinforcements) could alleviate this.