May as well add all of it. Once you open the packet, the yeast start absorbing water from the air. Wine yeast is much cheaper than beer yeast, by the way.
Remember one unassailable statistic, as explained by the late, great George Carlin: "Just think of how stupid the average person is, and then realize half of them are even stupider!"
"I would like to die on Mars, just not on impact." Elon Musk