That's funny. You need to consider the development of each castle, not just a battle between equal armies at the end.

Yes, if you compare the development, then the Conflux is definitely better, because phoenixes are incredibly cheap and quickly available! As you know, an archer costs 3 gems and 5000 gold, while a phoenix costs only 1 mercury and half the amount of gold... and besides, unlike a castle, the resource depot of the Conflux provides mercury, not useless stones and wood!!! As for building elemental magic, everything is great here! We build a second guild and then upgrade the 6th-level elements... (since the castle specializes in magic, the guild will only be a plus!) And the rest of the creatures are mostly not difficult to obtain!