I don’t recall the exactly what she said, but there were specific reasons for colony growth and health that they recommend the 1 gram per gallon.
It probably has to do with getting the colony going before other, undesired, critters start to develop. Good yeast crowds out its competitors. I read that in several articles (which ones, I don't recall).
Instead of colony size, temperature is probably a more effective idea. I've fermented whites at ~60F (my cellar in January) and the ferment took 3 to 4 weeks. Yeah, I realize that controlling temperature on a large batch in September isn't
quite that easy.
so if I used a bit more yeast than1g it would probably benefit my fermentation. Correct?
Yes, but with diminishing returns as the amount of yeast increases. A 5 g packet is designed to inoculate 5 to 6 gallons of wine or equivalent must, e.g., in good conditions the colony will grow, crowd out any competitors, and produce a good fermentation. If you add more than 1 packet, you
may get a faster start, but the end result will be the same.
OR -- Take 2 identical buckets of must. Sprinkle two 5 g packets on one and make a starter with one packet for the other, and gently pour the starter in the next morning. A day later I expect the batch with the starter will be fermenting better, as the yeast had 18-24 hours to multiply in a more ideal environment, so the initial colony was bigger and already vigorous. The batch with 2 packets has to develop in far less ideal conditions.
Given that a 5 g packet is marketed for up to 6 gallons of wine, you may be overthinking this. Make a starter and don't worry about it -- your wine will be fine.