I say ignore them, they are no use to us, and pose no threat to us AFAICT. They are dead meat as soon as we have Metal Casting, because then they wont even be able to escort workboats anywhere. They should be at war with both Mavs and Quatronia very soon.
FYI - Researching the uses of espionage and the EE I cam across something interesting...
Apparently, obsolete is a famous Wonderspammer and AFAICT the inventor and principal proponent of the
WE/SSE or "Wonder Economy." I had never heard of such a thing before, but basically it consists of getting the Pyramids, the Parthenon(and usually the GW) and then trying to get all the Wonders in your capital and spamming Great People, either to use for their benefits, or (usually) to settle them in you capital to make a Supercharged capital (hence the "SSE", for
Settled
Specialist
Economy. You run Bureaucracy and Representation civics for the whole game.
Now Im thinking that with obsolete at the helm, the Mavs are almost certainly headed for Pyramids, as it is a key component of the "WE/SSE". Some of the favorable conditions for the WE/SSE are: PHI leader, IND leader, An isolated capital that is rich in resources, particularly food and production resources, Island starts, Peaceful neighbors... any of this sound familiar?
One thing to remember, is if they are running the WE/SSE, then their capital will be a crown jewel for whoever captures it (which will either be Sirius of Quatronia, not us). For this reason we should remember to insist that the Mavericks capital be razed if captured. Also if they are wonderspamming, they might be trying for GW on 'Bora' (as Sirius called South Andromeda IIRC).
Anyway, according to the "WE/SSE" guides that I found, the two worst leader traits for the WE/SSE are CHA and IMP

so I guess that's out...
Ill try to find a link to one of the threads I read that was discussing the WE/SSE