Not really. Although i must admit, the calculator thing makes no sense at all. I was sort of thinking about it like this. Living things do their living thing, which generates power for life channelers. However, living things are also sotring up power and building themselves up as they live and grow. An oak tree might not produce a whole lot of power at once, but it will live for hundreds of years, so thats quite a bit of time to generate life power over. However, a death channeler only gets one shot of power, when the living things dies, but its a big shot of power. A 200 year old oak has had a long time to generate a build up power, so when it dies, its a massive amount.
If you think about it like that, life magic would be slow and steady, but death magic would get huge bursts at intervals. Over the long run they end up with the same amount of power. Circle of life, closed system, laws of thermo and all that. The only real difference in power would be the timing, and if you are looking at a large enough area, i am sure there is enough life and death going all over to balance it out.
Even in battle it would be balanced. Yes, there are lots of people dying, but at the same time, the ones who are still alive are struggling hard to live and thus would also be putting out more energy for life channelers. The corpses would also nourish the plants around the battle field as well as any scavenger.
You can only have death if something had lived, and everything that lives has to eventually die. Its a perfect balance.
