Pardon my begging of the predicate, but:
Why is there such an emphasis on throwing such a tremendously heavy amount of mass by sublight means?
Note: In asking this question, I am presuming that the target system is already, or will shortly be, incorporated into the stargate plexus; the question is moot if the intent is to land a fully Outback colony.
There is clearly a social virtue in having the colonial starter population travel in one giant (and thus slow) vessel or convoy; the shared experience will build community bonds vital to the enterprise (or else).
But otherwise why the logistical expense? That’s a bloody huge mass, and the rocket equation isn’t forgiving except by comparison to the relativistic rocket equation.
So populace aside, what is the virtue in one huge seed over a sprinkling of much smaller first-in drops, each with a designated setup for things like fuel-siphoning, positioning buoys, stellar power supply, and so on?