Personally, if I had been the leader of your empire, I would have first taken the relocation offer, and moved near the other relocated empires, but into separate sectors. And I would have arranged discussions with them on the subject of forming a single empire the better to provide everyone with the best technology, resources, and ships, and knowledge of game mechanics and so on. The eventual goal would be to form something capable of taking on Syndicate.
Aside from whoever is assigned to leader and vice-leader, setting each player's character to sector commander would simplify management, in that each person would be responsible for their own sector, similar to if they were running their own empire, and you'd have all the officers possible from the habitable worlds in your sectors, so you'd have personal fleets, but for best results you'd want to coordinate together, etc. You'd also all be looking for the best resources in your empire and directing them to the empire's chosen shipyard systems, so that you would all be able to make the best ships possible. (This is basically how Tymas was run)
Obviously you need to tech up for resource quality to matter - everyone's playing with low TLs right now still, from what I hear.
With single empires your resources will be lower quality, your tech won't advance as quickly, and you can easily be picked off one by one.
Pirate alts to scout (find resources, shipyards, trade routes, officer farms, etc) and sabotage are also a long tradition.