Just looked at the save.
The immortals in Dancing Banana, Unabomb, and Dynopolis can attack the gallic swordsmen immediantly. I recommend that they all attack the large stack, as the stack is closer to our core and poses more of a threat (however small).
As for rushing, I say we rush the Immortal in Grenadapolis and move the citizen working on the ivory in Carpetbomb to start working on the hill.. shorten down the gold spent rushing that Immortal.
The rest of our immortals should be in attack range within a turn or two.
By the looks of things, Unabomb will be the last city we lose. Rushed pikemen can move into Dancing Banana and Dynopolis immediantly giving Dancing Banana a defense of four pikemen and Dynopolis one. However, we have an additional 6 pikemen moving up from the south that should reach dynopolis in a turn or three.
I recommend taking some of the pikemen from dynopolis and Dancing Banana to defend our Immortals moving up towards the galls. If we move the immortals along with pikemen, we could minimize our loses.
We need that gold from the MIA though and as soon as possible.
With some luck this turn, we can start chanting "3 down and 7 more to go!"
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I think the real question is how far are we willing to take this? The galls will have destroyed three of our cities, alot of damage.
I vote on making sure the galls take just as much damage as we have. Once we remove the threat from our continent, shore up our coastel defenses and start building naval transports and knights. Then we ship 'em overseas and let the galls have a taste of what it feels like.