CG-1 has got me thinking about all the various implications of species choice that can go into a team, when you are able to chose your allies ahead of time.
There are several reasons to chose a particular species, such as battle synergy, expansion rates, econ balance, etc, but the one I want to talk about is Habitability. It should be possible to spread out your species choices to minimize bad habs and allow everyone to get good habs, without having to pass your good habs to someone else.
Grey habs have three features, Air, Water, and Temperature, and each of those can vary between 0 and 100 percent. Picture this as a three dimensional graph, with x, y, and z axes. You can visualize the space in this graph as a stack of eight cubes, 2 x 2 x 2, like a mini rubik's cube. Each of the eight cubs represents a corner of the hab range. The cubes are:
HHH = High Air High Water High Temp
HHL = High Air High Water Low Temp
HLH = High Air Low Water High Temp
So it seems to me that the best spread of species would be one where you had a species in the center of each cube. That way every hab would be very good for someone.
The center of the HHH cube would be 75-75-75
The center of the HHL cube would be 75-75-25
The center of the HLH cube would be 75-25-75
only drawback to this plan is that there are 8 cubes, and an alliance only has 4 members at most. So the best you can do is have all your species spread out, so that each one covers two cubes
For example, you might have one species straddling the line between HHH and HHL, 75-75-50
and another between HLH and HLL, 75-25-50
a third between LHL and LLL, 25-50-25
and the fine one between LHH and LLH, 25-50-75
so I wondered. how close is each species to the center of each cube? well that's a math question, so I did it in excel
the numbers in this table are the distance
of each species to the center of each cube, so smaller is better. OK distances are in the orangish squares, closeby species are in blue, and really close is in bold blue. so if you could manage to get blue in each category, you would have great coverage of all possible habs. I'll leave it to you to figure out whats possible