Suggestion: let's list some of the pros & cons of the various choices. Example - 1&5 minimize tropics, 2/3/6 have a moderate amount, and 4 has the most.

If divided into squares, 4 probably has the most that are landlocked, followed by 1,2,& 5, with 3 & six maybe more coastal bits. Having participated in several geofiction build-your-own nation games, I can say people are drawn to coasts - it's easier to envision connections & conflict. With landlocked territory one is really stuck with however your neighbors develop. Not to say interior spaces are uninteresting - if you want a silk road across vast desert expanses, skinny isthmuses won't be prospects.

In that vein, 2/3/6 seem to have the most semi-protected waters to become cradles of early shipborne transport, followed by the others. That's a maybe, depending on currents and wind patterns.

1/3/5 have some pretty isolated lands, depending on how proficient our explorers and colonists are (thinking flora & fauna as well as people). That would give us better rationale for wildly different races, critters, ecosystems.

Shall we say we're somewhere between sword age and cannons, maybe with great differences in development level? That doesn't affect the terrain, but it'll have bearing on the manmade features.

As far as inducement for voting, how about if those who vote - for anything! - get a say in the pool of continent & ocean names? Best if we have several to choose from for each, but to stick possibilities in the pool could be a perk. Sure, the myriad cultures on a fantasy world will have a myriad+1 names, in local tongues, but for *our* purposes it's a bummer to be referring to "landmass 3" and "ocean F". Common names won't tie one down - one's map doesn't even have to use latin script! :-).

A flaw in thinking, IMHO, when building a cooperative array of nations, is that many, many folk want their territory to be the best and brightest. That way lies the Lake Woebegon effect, where everybody is above average. We are pursuing this mostly to make maps, not so much to role play the nations and peoples, but acknowledgement up front that *nobody* is top dog should help. We are partly mitigating that tendency by chopping area up geometrically instead of by political boundaries, but the competitive mindset is grating to other participants. Not to say one's obviously nautical territory doesn't have extensive fleets, and considerable trade - just that I don't get to say that stretch over there outside my box is all vassal states to the Mighty My Own Empire.

What's Really Fun is the negotiation & compromise to get edges to match up.

What are some other deciding characteristics of the worldmap choices?