So, to build an embassy with the 4 civs on the other continent, you first have to take over an enemy coastal city (presumably only after you discover cannons) and build a boat. This limits your embassies to 2 or 3 civs until cannons I think. The same goes for when you want to take over london/edison etc when the enemy at the top of the other continent builds them. This can only happen after you build cannon stacks and take over enemy coastal cities on your own continent. As luck would have it, no one wants to trade or give you republic or any other juicy advances on your continent, if that's possible, which slows your development.

Also, since it's apolyton pack, it is possible I think for the super-power civ at the top of the other continent to have their wonder cities defended by interceptors and maybe even robot walkers by the time you arrive. Your cannon stacks can be defeated by counter-bombardment, or maybe the enemy even starts a preemptive war as you try to advance on their wonder cities. Enemy tanks and machine gunners with interceptor bombardment could wipe out your cannon stacks. With enemy robots your cannons are in real trouble.

So, you might be resigned to just attack your own continental enemy cities, but the city limit of 35 under communism limits your development.

You will still win, once you get robotics of course, which I assume you can always trade/demand/capture for eventually while biding your time on your own continent. But I do not know for sure. The enemy superpower might build alien life (in apolyton?) before you can get a robot stack up there to destroy them.

So, I am thinking this is the toughest map setup and game progression. I haven't actually seen exactly this, or any game which I could not win with robot walkers, evetually, but I think it might be possible -- say, if all enemy civs except the one superpower are really stupid and you just can't get robotics from anyone until it's too late? Maybe building tons of spies and trying to steal robotics from the superpower would eventually work, I never had to try it.

What do you think? Is there any setup tougher than this, or is my strategy missing something that would provide an easy win even in this situation?

I have not considered wes's medieval/modern mod here. My guess is, there is some map setup and game progression under those mods where you simply would not win no matter what you do, but I haven't tried them. Maybe next year when everyone else has moved on to ctp 2. Much thanks for any replies and comments.