First: Don't delay the start for everyone except tribes of 5+. This is too easy to abuse. Tribes can form and reform until at least one member has a tribal totem on every decent spot in the game. (Correct me if I'm wrong, but if a tribe drops to below 5, that totem doesn't go away, or at least doesn't go away right away, leaving ample time for a tribe member's alt to change it to a homestead if that is ever necessary at all, and still blocking a legitimate claim).

Do let large tribes (15+ or maybe 20+) choose a location and place their totem, with guide oversight. But only if the large tribes can agree amongst themselves on who is placing where. If they can't come to an agreement, they fail at politics and certainly shouldn't have any advantage over solo players and small tribes (that last part was aimed directly at those who claim solo players and small tribes need to 'play more politics' by the way).

Then all the members of the large tribes who have placed their totems must log immediately out of the game and not log back into the game until after the rest of us have had three hours or so to place our totems.

This way, no one can abuse an extra early start by forming and reforming tribes for alts and friends or by splitting into a bunch of 5+ or 10+ tribes for launch day to take as much of the map as possible.

Yet the truly big tribes don't have to worry about losing those areas most suited to large settlements.

It might also help with any possible lag issues.

It will put a stop to the big tribes pointing fingers at each other and going back and forth over totem placement on the 18th. With the advantage of a head start for tribes large enough to truly need it and with negotiation beforehand, every one of them will be able to find a suitable location.

This solution will completely eliminate complaints of special treatment based on beta seniority or any other special treatment, since the only consideration is the difficulty a truly large tribe would have in placing their totem properly on suitable land in the midst of a general land rush.