This is a simple fix really. Quit changing the size that tribes and clans have to be. Just give more junkpiles in remote areas.
I can run around out in the wilderness for hours in remote areas and find some really nice places to setup shop, but there isnt a junkpile for miles. A lot of wasted land out there. Such a shame really. I think you should make small junkpiles scattered thoughout remote areas. Part of the lagg problem could be from too many people crowded into a few clusters of zones where all the junk piles are.
For all that is good, untilize all the land currently available by encouraging outposts in remote areas by putting small junkpiles that scatter the landscape.