I recently had the chance to play the Napoleonic scenario in C3C. I liked the idea very much once I had started with few exceptions. The biggest problem I found was the map. With cities too close, production was a pain and nearly every pop center overlapped 3-6 squares. Cities that had existed at that time in history had to be skipped because even though the map was size huge, there still was not enough space to squeeze everything in with more than rudimentary historical accuracy. This got me to thinking, a dangerous prospect under the best of conditions.
I once played a board game called 'War in Europe'. It was basically a WW2 modular system with brigade to divisional size units. It was a bear to play and a minimum of 6 people were needed just to set the campaign map and units up in less than 12 hrs. It took up a garage size room when finished and took 100's of hrs to play. The one thing the game offered was its modular system.
The system broke the game down into individual operations, allowing you to start with just the Polish/German map, add Norway later, then France and the low countries, then Britain and so on. While I played the C3C Napoleon scenario, it got me to thinking about what could be a viable, easy way of making a computor map bigger. Rather than worrying with different zooms, why not just split a map into 4 sections that can be accessed through the mini-map.
For example, let's say you want to do WW2 in Europe with all of the geography that was actually used + extra for 'what if' possibilities? Using C3 as a model, it couldn't be done except on a very basic level. But what if the existing huge map was increased to 4 times it's size and put on to the mini-map so that each section was separated by ie. red lines, Calling these sections 1(NWest), 2(NEast), 3(SWest), and 4(SEast). During play, the map would be accessable by section. Section 1 might have part of Great Britain, part of France,the low countries, maybe Denmark and Norway and a small slice of Germany-Section 2 might have Sweden, Finland, Northern Germany, Poland, etc. and so on. As you play the map and cross over from one section to the next, the change to the new section would be no different than the present screen change that already exists when you move any unit. You could also select any section from the M-Map and scroll it like a huge map during game turn play, moving from section to section as needed. In a randomly generated game, actual play could start (and end) on one section (Depending on how many different cultures were allowed and what the victory conditions were) but you could expand to the other sections if necessary. By incorporating it this way, you basically have 3 (or more) additional maps the same size as the one you start on as back-ups for when your CIV goes 'Global'. The other sections wouldn't be accessible until you 'crossed the edge of the world' through whatever sea or land units you sent out. It would drastically change the entire concept of world expansion or 'Age of Discovery' without complicating the programability.
It would also allow wonders to be spread out-for example- on an Earth map, Forbidden Palace would not be available to Europe (section 1) but to Asia(section 2). Instead, Europe would have The Palace at Versailles, which would serve in the same fashion. Sun-Zu's War College would, in Europe, be Machiavelli's treatise. Both would offer the same benefit. Both could be built, serving only the building Civ within that culture. There are numerous other possibilities. Each different culture would have access only to wonders that were actually built by that culture with equivilants available where they could be found. The mixing and matching would make some wonders unavailable to some cultures, solving the 'indigenous wonder' situation by programming cultures and wonders to individual map sections.
The difference for game play is that your map would be 4 times larger (or 6, or 8, or even 10) than what is presently offered by C3 and so your ability to spread cities out in scenarios is improved. The technique would also allow scaling and manageability, not to mention an increase in map size that would offer a vaster range of more accurate historic scenario possibilities. Magnification would work pretty much the same as it ever has because each section would actually be its own map...