48 palaces in Massilia (some not always stable at "luxury" level due to limits on food production). Perhaps it could be tweaked a bit for greater stability. Rating of 100-100-100 (maximums).
This layout could probably support 40-44 very stable luxury palaces.
Supplying the palace blocks from both ends of the block and through 3 gates allows more markets to be within "striking" distance of more palaces, which permits a larger loop than is usually seen. It also reduces congestion just outside the gates. Some tweaking was required to force the charioteers from one chariot source to go down the proper road. For some reason they wanted to go the long route which prevented advancement of some palaces.
This is probably the absolute maximum number of palaces possible at this level. In any case, I would be very interested in seeing a layout that can support more.
This city contains only 30 palaces (28 luxury, 1 large, 1 medium), which will change over time since houses frequently devolve and evolve. Within a few years there will be no palaces, since the city produces no oil (and insufficient fruit, pottery, and timber/furniture). It is a reasonable example of a Massilia with a lot of palaces at one instant, but is very far from being stable.