Generally, the more people sharing a white gas stove, the more efficient it's going to be on a per-person basis. A certain amount of fuel gets wasted on priming and start up. A certain amount of fuel gets wasted on shut down. That amount is about the same whether 3 people use the stove or 1. If you spread that waste out over three different people, the per person amount is reduced.

It's also generally more efficient to heat three cups of water at one time than it is to heat 1 cup three times.

All those things add up to greater efficiency with a shared white gas stove. This is why I don't say something like "bring 2 fl oz per day per person." A group is typically more efficient. If you bring per person the amount you'd bring when you just go alone, you'll likely end up with a lot of leftover fuel.

HJ