Manual Initial Troop Placement

I have seen it on another site somewhere, can't remember where.

At the start of the game, players can choose which territory their troops start on up to a maximum of 3 troops. A single troop is placed on a territory and then the following player does the same until all troops are placed. Any territories with no troops placed on become neutral.

This has been proposed many times, and never have I seen a good answer to this question: How would this work fairly and nicely in a long term game, without a game taking weeks to setup?

sametime manual placement in fog, and game starts consecutively when all have placed.
it works great and would be perfect for d12 initial placement option.