I don’t really have any instant fix or plan, but I have been many times on both sides and have tried different approaches to keep things even. Now I am taking a beating in a small fam, but I would not want to see secession or divide my fam.
Both secession and assimilation by surprise are not fair. Such actions should be planned pre-round, even though exact details wouldn’t be shared with players, so they cannot try to avoid circumstances when features are triggered or to try to trigger them when it suits them.
Secession is not a fix. If small fam explores newly explorable planets and big fams are allowed to attack those, they will not be able to keep them. Big fams take them back. If big fams hit the planet amount roof and are not allowed to gain any planets, without losing some automatically, their round is over. I would just claim moral victory and wait for next round.
Assimilation is not nice either if the small losing fam is divided to different families. IC is social game and if you find someone who is good company in chat and you play well together, you don’t want to suddenly just turn your fleet against your friend. Also, I would not want to play with some big fam bully, who has farmed my fams planets half the round.
Assimilation in a form of vassalage/alliance could work better than dividing families. Smallest fams rarely have bad blood between them. Usually they even have had very nice war between themselves. When they are getting too small to compete with bigger fams, they could be allowed to form an alliance. Another option would be that when bigger fam defeats smaller fam, instead of just taking hundred planets by mass attacking and 50 more for NAP, they could either take smaller fam as a vassal. That being like alliance, but bigger fam calls the shot for both families. Another option is that bigger assimilates smaller fam. If these options need both fams acceptance (leader option or even majority vote in fam), it could keep fighting more civilized. Of course there should be certain restrictions for circumstances when these options come available to keep everything fair for bigger fams and exact details need not be known. Assimilation/vassalage should not make the combo biggest fam, but just a contender.
Another way to make staying big harder is to boost big empires’ costs and include some penalty to units also, not only for buildings. Portal prices could also be much higher with bigger planet amounts, so planet fat banker/ressie just could not portal all planets and have droid army keep them all save.
There could be a penalty to opp defense also. Bigger empire/fam is more loose society and easier to infiltrate for intell operatives. Opps are usually small fams only weapon, so why not make it more powerful?
When we have implemented pre-round activity checks and families have less inactives from the SOR, we could also try to have more and smaller families. 4-5 players? For a long time there has been around 8-10 spots per family. Winning families have had most active players, losers have had one or two actives and few semi-active. With 4-5 spots and pre-round checks activity could even out a bit.
I also like the idea of scrapping the main fleet concept of defending portalled planets. Portals could be only instant means of transportation and fleet would be divided to planets as stationary forces. Before attacking and sending fleet to attack enemy, it should be gathered to one portal first and then sent. There could be even a spell and opp to gather intelligence of approximate fleet movements and strengths to anticipate enemy actions a bit. But well, that could be a concept for some HC micromanagement galaxy.
One option to make things different, would be to change portals from instant travel to huge speed bonus between two portals and maybe even make traveling slower. Exploration and fighting would be more local. If it would take 200 ticks to travel from one side to other side of galaxy without portal in between and 20 with portal, families would not be spread out or at least would be more vulnerable if they spread around too much. Their fleet would be thinly spread too and it would be slow to move them to hot spot from another.
Just throwing some ideas out there. Some a bit radical…