A friend and I bought this game today and played for the first time. Early on we identified the power of the Cerberus to guard choke points, and soon had enough incense to build entire walls of them. Then, when combined with Yggdrasil, we filled most of the map with Cerberus' leading to a large number of tasty meals on the doppelganger units from the other side. Suffice to say, the last 30-40 turns were just End, End, End. I'm not sure if we just had a perfect storm of a game, or this strategy is actually quite broken, but many laughs were had. I can only assume that this game is poorly balanced for multiple players due to the turn advantage, which may have been the reason we were able to afford so many Mythological creatures.
Even without Yggdrasil, the Cerberus might need some tweaking. Most of the game seems to be designed around creating chaos, yet the Cerberus goes against this by allowing two key forms of control. Firstly, pretty much every basic in the unit dies trying to pass it, so it can guard a town essentially infinitely. Secondly, it blocks units of the same team, so it can even be used to protect opponent towns, by stopping the unit AI from destroying them. This lets you guide large numbers of units into chokes filled with Cerberus and get a lot of easy kills.
Interested to see how the game is tweaked in the coming weeks/months!