Bismarck worked out fairly well, I'd actually love to see more battles take a different approach like that... Kind of sick of the same standard "Fight in this ring" encounters, granted Bismarck wasn't much different compared to that, but the scale made it more entertaining regardless.
We could have, for example, have a battle with Alexander where he is stomping across the countryside and we have to stop him before he reaches whatever. We're on an Airship/s, flying alongside him, fighting off Illuminati before "docking" to crawl inside part of Alexander and blow up something to slow him down, eventually getting access to his core to finish him Bahamut Prime style. That would give us all the grandeur of fighting a full size Alexander, while still giving us a proper fight in the end, unlike Bishmark, who apparently died because we popped a zit?
Wouldn't work with the current raid format, of course. Can't split that fight over several updates, but why did Alexander need to be summoned after 3.0 anyway? I mean he isn't doing anything, wouldn't it have worked better to just have the Illuminati up to something, so we storm their stronghold (Raid 1). Then we find out what they're planning, and go to where they're planning to summon Alexander (Raid 2). Then they ultimately succeed and we get Alexander finally making his appearance and actually giving us reason to worry. Much better than "Oh no, Alexander fell off the short bus", that would actually build hype for his appearance, rather than the current situation that just has him in such a depressing state...
Shame they wanted to make him part of the map... I mean, we can't even fly around him properly anyway, what was the point? Imagine if he showed up on the coast you can see from Idyllshire? Then every update he draws closer. Much better. Kinda like how Dalamud was in 1.x, heck that was one of the best parts of 1.x... So many things they could have done with Alexander, and instead we just get him slowly standing up... Sigh...