Update on my Qin-island game here (I should be posting in the stories forum, but oh well)...
I started on the grenadiers a bit too late. Napoleon declared war, dropping 3 galleons of grenadiers, catapults and knights right next to my 2-religion holy city, defended by only 2 grenadiers. I start moving every grenadier (about 1 per city, as well as upgrading some of my axes, toward my holy city, but there's no way to keep from losing it. I lose the city, retake it, and lose the city again...
Then...Japan (I thought this was Montezuma with the last post, but it's actually Japan) declares war and does the same thing on the
other side (where I just moved my grenadiers from, leaving only a single longbow for defense).
3rd turn of war, I retake my holy city from France, finishing off france there, but there's nothing left except 2 shrines and an academy. This will be prove devastating to my lead. The Incas now hold the #1 spot.
Meanwhile, Japan captures my *best* military city on the west side. This one had pretty much all the happiness/health upgrades and was about to build Heroic Epic. Razed. Bastard. My troops are moving towards Japan's and start killing them off the next turn...
...which was the turn 2 more frigates from Napolean drop by and retake my holy city.
After a few more turns, I get everything under control, but this leaves me in 4th place. I had spent a few no-research turns to afford upgrading axes, plus switched to police state/theocracy. Heck, even Gandhi passed me on techs. Perhaps I should have caved in to Napolean's and Tokugawa's demands when we met?
OK, now things are looking up again and I'm starting to rebuild (still at war, so more are coming) and garrisoned every town with grenadiers. I've also got some more frigates, researched Cavalry with one horse coming and rifles in 2 turns, but what's this?!
Three frigates from Napolean coming toward my holy city, filled with rifles, grenadiers and catapults!
But wait! There more!
Japan is coming from the south with three frigates, as well.
They both land on the same turn. Napolean takes my holy city again 2-3 times, Japan razed another city (one of my better commerce cities too)
This is where I'm at now. My domain is currently safe, but theres no peace in sight. They both want my holy city for peace.

I'm in 3rd place again and researching railroads, not looking too bad and gaining ground again, but this tag-team war really cost me. I wont lose any more towns after I get rails hooked up, with artillary coming soon after. Incas are definitely still my favorite for space race victory in this game. He's busy killing off Gandhi and when he's done there, my guess is he'll jump way ahead of the rest. My "friends" are India and Persia and they are trading techs, but I had to cut everyone else off just to make them happy. Also had to go free religion. Everyone else who is not at war with me yet, likely will be soon.