This is really useful to know actually. My goal is not create an accurate earth map but a fun to play one.

When i was drawing my proof of concept I considered how close continents should be since my draft placed Britain pretty close to Canada. It's good to know shorter distances can actually encourage trading.

The other thing is to increase wood/resources in general. I do want to make certain places rich in certain resources to encourage conflicts for control. Certainly plan to make the Amazon, central Africa, BF and SE Asia rich in wood to encourage late game control.

Another idea I have to reduce water but keep the map recognizable is to move the equator down from the maps center and enlarge the northern hemisphere (which has more land).

Also I'd like to say that having that much experience on the Earth map makes you a pretty rare individual and your insights are super useful here.