Too bad the Amazon Kindle charger isn't in the mix, it is my favorite just because it is so tiny and relatively high output. Would have liked to see same analysis for it.
The chargers look like they'll work together. For example, the Kindle charger will make my pocket camera light up its charging light, but after a minute or so, it goes out, as if the charge has completed. In fact, though, the battery is still dead. The other combinations of cell phone / camera / Kindle chargers are similar.
In real life charging is also limited by the battery temperature for safety reasons. If the battery becomes too hot during charging (because of the environment temperature, poor ventilation or just because the device has a huge consumption while charging) the charging will stop and will start again when the battery cools down. This is why we do not see chargers with bigger Amp rating: the batteries are limited to a current that doesn't get them too hot.