most good warmongers are actually really good players, warmongering to build a larger empire wich flows onto more ciries-more prod/research. Even when playing a builders game it is worthwhile doing some early axe rushes etc for the required land. warmongering doesnt make it unsustanable. i often warmonger to gain land, and probably keep more cities than i should (i see some GOTM warmongerers razing nearly everything), turning captured cities into productive cities may take some time, but the resulting huge teritory fuels even larger production and war mongering. upkeep may be a pain, but once the newly captured cities build their required buildings and their cottages level up then they also add to the productivity and tec research speed. thus all fueling a even larger army and more war mongering.
Warmongering->teritory
teritory->productive teritory after time
productive teritory->tec lead
tec lead->more war mongering.
in such a large map good players would be able to consolidate their captured lands while still continuing to expand. having the largest teritory flows into more power. on such a map setting a war monger would do MUCH better than a turteler just building. so how can you state that warmongering is flawed when it gives the necisary decicive advantage over the AI.
How can you not account for the quadratcially mounting costs of maintenance?