you can obtain balance in other ways that pure mirroring of a map, (although for competitive purposes you still need to play both sides like you play on both sides of the field in football). Positional advantage as in your examples is just one of many factors that can be used to obtain balance.
A capzone can be super hard but the total map still balanced. A team could be given more time for a capzone, no matter how small the chance of success ,statistically eventually you'll make it. One side can have a shorter spawn time than the other side. One side can spawn closer to the cap than the other side. Weapon load outs could be changed or reinforcements could be lower for one side (although that would only work as a balance method with individual reinf).
Its all about a statistical balance here, aka if you play a map 1000 times that the axis win about 50% of the time. Believe it or not Basovka is actually pretty balanced in that sense (at least in clan matches as I don't have public match statistics). Player amounts and how good sides work as a team affect the balance a bit as well. Which is why its important to know what group of people (could be an average) a map is created for.
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If anything I fear that with countdown we might see too many cap zones that offer hardly any territorial advantage to the defenders, as the balance feature of different reinforcements, respawn time, and spawn distance cannot be used with only 1 life.
Which is exactly why I would like either of the 2 solutions below:
1: Give the attackers some sub objectives, they can clear to respawn, so the attackers can respawn a bit more than the defenders.
2: Allow the attackers to replay an attack for a cap-zone if they loose it for X times. So the defenders loose when the final cap is captured by the attackers, and the defenders win if they win against the attackers for X times.
edit: just created a thread about this
http://forums.tripwireinteractive.com/showthread.php?p=596865#post596865